Monthly Archives: December 2019

Growth and yield of different leaf-type lettuce cultivars grown in protected and open field cultivation

Authors: Zenaida C. Gonzaga1*, Lou Mark S. Fuentes1, Othello B. Capuno1, Jessie C. Rom1, Ana Linda G. Gorme1, Hubert B. Dimabuyu1, Dhenber C. Lusanta1, Sandra McDougall2, Adam D. Goldwater3 and Gordon S. Rogers3

ABSTRACT

Leafy vegetable production in the Philippines is less diversified than many other countries, especially those used in salads. As a result, Filipino farmers are less familiar with production of leaf-type lettuce that is increasing in popularity with consumers. Therefore, two separate experiments were conducted simultaneously in open field and under bamboo house-type protective structures roofed with plastic to evaluate the performance and profitability of different leaf-type lettuce cultivars. Each study was carried out in randomized complete block design with five treatment cultivars and three replications. Most cultivars grown under protective structures had higher marketable yields than those grown in the open field. Despite plants grown under protective structures incurring higher production costs compared to the open field, higher marketable yields under protective structures resulted in higher net returns. Among the five cultivars, Green Span gave the highest return in the open field and Green Tower under the protective structure. Smaller lettuce cultivars produced lower yields than bigger cultivars.

Keywords: asteraceae, food safety, rain shelter, conventional, soil splash


Annals of Tropical Research 39(SUPPLEMENT B):100-107(2017)
DOI: https://doi.org/10.32945/atr39sb7.2017
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Efficacy of selected biological products on broad mite (Polyphagotarsonemus latus Banks) in sweet pepper

Authors: Reny G. Gerona1*, Jesusa C. Jimenez1, Esmer V. Avelino1, Valeriana P. Justo2, Raffy Danggoy3, Melba B. Agosto1, Bernardita I. Lauro1, Melody G. Atanoza1, Sandra McDougall4 and Valerie Draper4

ABSTRACT

Four studies were conducted to evaluate the efficacy of potential alternatives to miticides against the broad mite (Polyphagotarsonemus latus Banks) population on sweet peppers grown under protected and open field cultivation at Visayas State University, Baybay, Leyte and one field study was conducted at USTP, Claveria.
Three of these four comparative studies reported that fruit yield was higher under the protected cropping structures than from the open field cultivation; the other study found no significant yield difference. The miticides: abamectin, dinotefuran and sulfur treatments, consistently resulted in the least damage to the plants in both open field and protected cropping plots and higher marketable yields.
The botanicals: 7-Herb Plus, curry plant, onion, and garlic + chilli pepper extracts, and both brewed and unbrewed vermitea showed less mite damage in peppers than the water control treatments but were not as effective as the miticide treatment in both protected and open cultivation. Neem leaf and garlic extracts had less mite damage than the water control in the protected cropping experiment but not the field experiment. Kakawate extract and the insect fungal pathogen, Metarhizium anisopliae SPW isolate were ineffective against mites.

Keywords: Broad mite, sweet pepper, botanicals, Philippines, protected structure, open field


Annals of Tropical Research 39(SUPPLEMENT B):80-99(2017)
DOI: https://doi.org/10.32945/atr39sb6.2017
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Biocontrol potential of Bacillus thuringiensis var. aizawai and Metarhizium anisopliae SPW isolate against insect pests of pechay and lettuce grown under protected and open field cultivation

Authors: Reny G. Gerona1*and Bernardita I. Lauro1

ABSTRACT

Insect pests are one of the constraints in lettuce and pechay production. Although synthetic chemical insecticides are widely used, organic growers are interested in using alternative options which have no toxic residues. This study aimed to evaluate the biocontrol potential of Bacillus thuringiensis var. aizawai (Bta) and Metarhizium anisopliae (Ma) SPW isolate against insect pests of pechay and lettuce grown under protected and open field cultivation. Weekly spraying of each treatment was done using the recommended rates (RR) of application: Ma at 3L spore suspension per 13L water (1×108 spore concentration); Bta at 20g per 16L water; cypermethrin 5EC at 30mL per 16L water. Insect infestation was monitored weekly based on insect count and damage ratings. Yields were recorded at harvest. Results showed that application of either Bta, Ma or cypermethrin significantly reduced populations and damage of Spodoptera litura Fabr. and Plutella xylostella L. Pechay plants applied with Bta and Ma showed higher yields than cypermethrin in both types of cultivation. These findings suggested that Bta and Ma SPW isolate were effective against S. litura and P. xylostella and can be used as an alternative non-chemical option for their management.

Keywords: entomopathogens, alternative insect management, pechay, lettuce


Annals of Tropical Research 39(SUPPLEMENT B):69-79(2017)
DOI: https://doi.org/10.32945/atr39sb5.2017
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Efficacy of wood vinegars for the control of Sclerotium rolfsii affecting tomato (Solanum lycopersicum L.)

Authors: Lucia M. Borines1*, Merlita M. de la Cruz1, Fely R. Cañete1, Zenaida C. Gonzaga1, Othello Capuno1, Gordon Rogers2, Sandra McDougall3 and Len Tesoriero3

ABSTRACT

Wood vinegar is claimed to be pesticidal by several researchers but its bioefficacy data on specific pests are lacking. This study evaluated 17 wood vinegars against S. rolfsii causing sclerotium wilt in tomato in vitro and in vivo. Eleven out of 17 wood vinegars showed direct inhibition to S. rolfsii at 2% concentration. These include wood vinegars from bamboo, banaba, cacao, caimito, ipil-ipil, lumboy, madre de cacao, malunggay, mango, panyawan and rice hull. These wood vinegars varied in their effectiveness in inhibiting the colony growth of S. rolfsii in vitro, with wood vinegar from ipil-pil showing the highest inhibition to the fungal growth followed by wood vinegar from lumboy. Wood vinegar from ipil-ipil however was the most phyto-toxic to tomato. The wood vinegar from lumboy, is promising since it was one of the most effective in reducing the disease severity in inoculated seedlings and was one of the least phyto-toxic. The wood vinegars from malunggay and panyawan, although not very effective in vitro were the most effective in reducing the disease severity in inoculated tomato plants and retained their effectiveness longer. Lower concentrations of the wood vinegars as a whole (0.2%) was the most effective in reducing sclerotium wilt severity over time, even though this concentration showed no direct inhibition to the fungus in vitro. This finding implies that wood vinegar may possess another mode of action in controlling the disease aside from the direct antifungal activity, which could be induction of resistance in plants to specific diseases.

Keywords: pyroligneous acid, Southern blight mokusaku tomato antifungal


Annals of Tropical Research 39(SUPPLEMENT B):54-68(2017)
DOI: https://doi.org/10.32945/atr39sb4.2017
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Managing major diseases of tomato (Solanum lycopersicum L.) using resistance elicitors and protected cultivation

Authors: Lucia M. Borines1*, Rezel M. Sagarino, Fely R. Cañete1, Elvira L. Oclarit1, Zenaida C. Gonzaga2, Sandra McDougall and Len Tesoriero2

ABSTRACT

Diseases, particularly bacterial wilt caused by Ralstonia solanacearum is a major constraint to vegetable production. Protected cultivation has been proven effective in reducing disease incidence but additional control measures need to be integrated in highly infested soils to mitigate the losses due to diseases. This paper reports the effect of resistance elicitors, particularly chitosan, acetylsalicylic acid and SiO2 in mitigating bacterial wilt disease problem and other naturally occurring diseases in two field trials. Two hundred ppm chitosan, acetylsalicylic acid and their combination had reduced bacterial wilt incidence and increased the yield of tomato under protected cultivation, but not in the open field. SiO2 was not able to reduce bacterial wilt incidence in tomato but had reduced the nematode count, especially Rotylenchulus sp. in the roots, particularly when drenched. Protected cultivation still proved effective in reducing bacterial wilt incidence in both experiments. It’s potential to protect crops against bacterial wilt is further enhanced by the application of chitosan and acetylsalicylic acid, most especially the combination of these treatments. The potential of chitosan and acetylsalicylic acid in protecting plants in the open field against bacterial wilt may be enhanced by the addition of a sticker.

Keywords: Chitosan, acetylsalicylic acid, SiO2 Control resistance booster


Annals of Tropical Research 39(SUPPLEMENT B):40-53(2017)
DOI: https://doi.org/10.32945/atr39sb3.2017
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Inventory and incidence of plant diseases affecting vegetables in selected areas in the Visayas and Mindanao

Authors: Lucia M. Borines1*, Joy Adeline C. Nuñez, Rezel M. Sagarino1, Fely R. Cañete1, Elvira L. Oclarit1, Reny G. Gerona1, Sandra McDougall2 and Len Tesoriero2

ABSTRACT

The identification of different vegetable diseases in a particular area is key to managing them. An inventory of diseases affecting important vegetables was conducted in selected areas in the Visayas, and Mindanao. The vegetable diseases were documented in Leyte, Samar, Biliran, Bohol and Claveria Misamis Oriental. Disease surveys were conducted and samples were brought to the laboratory for diagnosis. Pathogenicity tests were conducted for uncommon diseases and PCR and nest PCR assays were done for suspected Phytoplasma diseases. The most common and major disease that affect vegetables in Eastern Visayas is bacterial wilt caused by Ralstonia solanacearum which attacked tomato, pepper, eggplant, bittergourd and was also detected in a wilt infected lettuce. Downy mildew is another which affected bittergourd and pechay. Cercospora diseases were found to commonly affect pepper, eggplant, tomato and bittergourd. Phytophthora diseases were common in tomato, eggplant, pepper and pechay. Fusarium wilt had affected tomato and pepper in Claveria Misamis Oriental, but not common in Eastern Visayas. Emerging diseases were recorded such as Phytoplasma and Corynespora cassiicola which affected tomato and bittergourd, bacterial canker, bacterial speck, target spot, Septoria leaf spot and pith necroses were also found affecting tomato. Information gained from the inventory informed the production of extension materials aimed at farmers and farm extension officers.

Keywords: Phytoplasma, tomato, ampalaya, eggplant, lettuce, pechay, sweet pepper, emerging diseases


Annals of Tropical Research 39(SUPPLEMENT B):22-39(2017)
DOI: https://doi.org/10.32945/atr39sb2.2017
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Survey on farm practices of small-scale vegetable farmers in the Southern Philippines

Authors: Moises Neil V. Seriño1*, Glorybeth Castillo and Jessa Ruales

ABSTRACT

This study aims to survey the farm practices of small scale vegetable farmers, evaluate gender roles in farming and assess the changes in farm income of farmers engaged in integrated crop management. The respondents of the study include randomly selected small-scale vegetable farmers trained under the farmer field school (FFS) in Bohol, Leyte and Samar. Randomly selected non-FFS farmers serve as control group. Information on farm practices between non-FFS and FFS respondents are used in determining the changes in farm outcomes. Results show that FFS and non-FFS farmers mostly planted eggplant, bitter gourd, beans, sweet pepper, pechay, squash, tomato and okra. The farm areas of surveyed respondents are mostly located around 10 kilometers away from their primary market with an approximate traveling time of half an hour. During the baseline survey, FFS farmers indicated that they are mostly unsatisfied with their current vegetable production in contrast to non-FFS farmers who expressed satisfaction with their current production. However, in the follow-up survey FFS group expressed relatively higher optimism than non-FFS group in terms of their vegetable production suggesting that the project interventions were able to encourage small scale farmers to incorporate necessary improvements in their practices. For gender roles in vegetable production, men are into labor intensive tasks while women focus mostly on record keeping and monitoring sales of vegetables. Lastly, employing the method of difference in difference shows that impact of farmer field school on integrated crop management increases vegetable farm income by around PHP4,300.00 per year per farm.

Keywords: farm practices, gender roles, vegetable profitability, impact assessment


Annals of Tropical Research 39(SUPPLEMENT B):1-21(2017)
DOI: https://doi.org/10.32945/atr39sb1.2017
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Most Significant Change Experienced by Farmers from Adopting Rainforestation Farming

Author(s): Genie Leen M. Velarde, Rotacio S. Gravoso, Editha G. Cagasan and Christina A. Gabrillo

Abstract

The Visayas State University (VSU) developed the rainforestation farming (RF) system to replace the more destructive forms of kaingin or slash-and-burn practices commonly practiced by farmers and provide them with a stable and higher income. VSU disseminated the technology through training and establishment of demonstration farms coupled with various extension materials. The most important changes experienced by farmers from adopting RF were increase in income, greater social skills, improvement of their water and air conditions, and enhancement of biodiversity in their rainforestation farms.

Keywords: project impacts, technology adoption, tree farmers, participatory monitoring and evaluation, Leyte

Annals of Tropical Research 29(3):109-122(2007)

The Contribution of Farm Products to Farmer’s Livelihood and Household Consumption in Leyte, the Philippines

Author(s): Carol A. Neal

Abstract

This paper describes the agroforestry farming systems through which crops, trees and small farm animals are produced and consumed by three farming families on Leyte Island, the Philippines, and the extent to which they contribute to the farmers’ livelihoods and wellbeing. A survey using semi-structured personal interviews was carried out to obtain data on cost savings of farm grown products consumed, health benefits derived and costs incurred in managing and maintaining each farm. There were notable differences in crop-tree arrangement and management methods used by the farmers. An estimate of the amount of product that was consumed by the households was conditional on crop choices and intensity of effort and inputs and offsets from off-farm income. Informal arrangements for bartering food, and coconut and bamboo product sharing for community use, made precise valuation of these products difficult, but comparative values against local market prices were placed on marketable produce. Labour and other inputs between the farms varied widely, depending on the type of product. In addition to crops grown as a source of income, portions of farm products were grown specifically for home consumption, and some non-consumable products were exchanged between households. The farmers had a basic understanding of the nutritional value and health benefits of all the food products they consumed for daily energy, health and medicinal purposes. They also believed that consuming their own farm-grown produce generated savings compared with quality and value of the same product from the local markets.

Keywords: agroforestry farming systems, food quality, livelihood, nutritional value, savings benefits

Annals of Tropical Research 29(3):91-108(2007)

Biomass Equations for Tropical Tree Plantation Species in Young Stands Using Secondary Data from the Philippines

Author(s): Ma. Regina N. Banaticla1,3,4, Renezita F. Sales1 and Rodel D. Lasco2,3

Abstract

Estimation of the magnitude of sinks and sources of carbon requires reliable estimates of the biomass of forests and of individual trees. Equations for predicting tree biomass have been developed using secondary data involving destructive sampling in plantations (mostly less than 10 years of age) in several localities in the Philippines. These equations allow estimates of carbon sequestration to be made at much lower cost than would be incurred if detailed stand inventories were undertaken. The species included in the study reported here include Gmelina arborea Roxb., Paraserianthes falcataria (L.) Nielsen Swietenia macrophylla King and Dipterocarp species in Mindanao, and Leucaena leucocephala de Wit from Laguna, Antique, Cebu, Iloilo, Rizal, and Ilocos Sur. Non-linear regression was used to derive speciesspecific, site specific and generic equations between yield and diameter of the form y = αDβ. Equations were evaluated based on the correlation coefficient, standard error of estimate and residual plots. Regressions resulted in high r values (>0.90). In some cases, non-homogeneous variance was encountered. The generic equation improved estimates compared with models used in previous studies.

Keywords: Carbon sequestration, non-linear regression, generic equations

Annals of Tropical Research 29(3):73-90(2007)