Category Archives: Volume 3 No. 2 (1981)

Innovative Performance of Coconut Farmers in Leyte and Southern Leyte, Philippines


Author: Dolores L. Alcober

Abstract

The innovative performance of coconut farmers in Leyte and Southern Leyte was determined. The respondents had an average age of 52 years with an average farming experience of 23 years. Their mean educational attainment was 5 years; average number of household members, 6, and an average annual income of P5,969.47. Majority were owner-operators and slightly over one-half were part-time farmers. They had an average farm size of 3.29 ha. The respondents adopted an average of 5 recommended coconut production practices and had high adoption scores in selecting the seedlings for transplanting, preparing the seed nuts for germination, selecting the planting materials, replanting, laying out the field before planting, and intercropping. The practices which had low adoption scores were: plowing, controlling pests, controlling diseases, and application of fertilizer. Reasons given for non-adoption were: ignorance of the advantage of the practice, not certain of its success, lack of money to buy the farm inputs, and did not know how to do it. Sources of farm information, aspirations in life, perception of coconut farming, attitude towards modernization in coconut farming, annual gross income, size of farm, production credit and expectations from coconut farming were found significantly related to innovative performance. Farmers were beset with ma, problems, such as low price of copra, low yield, no working animals, poor sharing system, frequent occurrence of typhoons, and presence of rats. Preparing the seed nuts for germination and plowing were considered “very simple” to understand and use; intercropping, replanting and selecting the seedlings for transplanting, “simple”; selecting the planting materials, laying out the field before planting and fertilizing, “difficult”; and controlling diseases and pests, “very difficult”.

Keywords : Coconut farmer. Demographic characteristics. Recommended practice. Innovative performance. Implication. Leyte. Southern Leyte.

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Effects of Different Portions and Length of Storage of Cuttings on the Growth and Yield of Sweet Potato


Author(s): C.A. Eronico, R.G. Escalada and R.M. Trenuela

Abstract

Storing cuttings of BNAS-51 variety of sweet potato for 15 days caused significant decrease in leaf area index (LAI) during the first two months after planting. However, there were no significant variations in LAI and fresh herbage at harvest. Generally, plants that originated from the unstored cuttings produced significantly higher marketable tubers, total yield and harvest index compared to those which developed from stored cuttings. Yield of non-marketable tubers was not significant-Is affected. As far as source of cutting is concerned, plants that developed from unstored apical cuttings produced significantly higher LAI, marketable tuber, and total yield compared to middle and basal cuttings, except in weight of fresh herbage. Nevertheless, plants from stored apical, middle and basal cuttings assumed similar LAI during the entire growth of the crop and produced the same yield and yield components.

Keywords : Sweet potato. Growth and yield. Length of storage. Leaf area index. Harvest index.

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Manipulation of Cultural Practices for ipil-ipil and Its Effect on the Intercropped Cassava


Author: Rodolfo G. Escalada

Abstract

Pruning and intercropping affected plant height and fresh herbage yield of ipil-ipil. Both parameters declined as the crop was cut back periodically. Plant population also compounded the effect. At high plant population, the pruned plants developed thin and elongated stems which reduced herbage yield per plant per unit area. However, the higher number of plants per unit area compensated for the reduced vegetative growth. High herbage yields were obtained at close planting distance. The cassava plants competed intensely with ipil-ipil for light and space. Due to rapid growth and development of the pruned ipil-ipil, growth and development of plant parts and formation of cassava tubers were greatly affected as manifested by the higher yield of the monoculture crop. A planting distance of 3 m x 15 cm for ipil-ipil resulted in the production of reasonable tuber yields per hectare of cassava.

Keywords : Pruning. Intercropping. Ipil-ipil. Cassava. Herbage yield. Tuber yield.

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Post-harvest Fumigation of Tubers for the Control of Sweet Potato Weevil


Author(s): A. L. Acedo Jr., E. C. Manoto and O. K. Bautista

Abstract

The use of ethylene dibromide (EDB) and phostoxin in controlling sweet potato weevil was evaluated. Larvae and pupae were effectively controlled when EDB was used at the rate of 32 ml/cu m. However, phostoxin at 10.5 tablets/cu m was more effective than EDB in controlling the different developmental stages of the weevil. This showed the greater potential of phostoxin in controlling the pest aside from its superior characteristics as compared to that of EDB. Phostoxin is less toxic (LD50 = 50 ppm) than EDB (LD50 = 20 ppm), and is easier to apply, hence, an in-expensive fumigation chamber could readily be rigged up in rural areas utilizing this fumigant.

Keywords : Sweet potato. Weevil. Cylas formicarius elegantulus. Fumigation. Ethylene dibromide. Phostoxin. Chemical control.

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Effect of Rust and Mottle Virus Infection on the Growth and Yield of Groundnut


Author(s): E. H. Estrada and M. K. Palomar

Abstract

Two-week old groundnut seedlings (Coronadal variety) were inoculated with rust, Puccinia arachidis Speg. and mottle virus alone or in combination, either simultaneously or a week earlier than the other. Plant height was significantly reduced in plants inoculated with rust a week earlier than the virus but was not affected when each of the pathogens was inoculated alone, simultaneously or when virus was inoculated a week before the rust. Flower formation was delayed in plants simultaneously inoculated with rust and virus and in plants inoculated with rust first before the virus. Neither the different disease combinations nor groundnut mottle alone had a significant effect on maturity, however, rust alone caused the plants to dry up and wither before the expected maturity date. Plants simultaneously inoculated with rust and mottle virus had the least number of rust pustules per leaflet and fewer number of rust-infected leaflets. When yield was expressed in terms of weight of dried seeds, greatest reduction (50%) was obtained in plants inoculated with virus first and rust after one week, followed by plants inoculated first with rust then virus Inter (43%). Least percentage reduction (19%) was obtained in plants inoculated with virus alone but this had greatest seed discoloration. The least weight of 50 seeds was obtained in plants inoculated with rust first one week prior to virus inoculation. Yield in terms of number and weight of productive pods and number and dry yield of seeds was least in plants inoculated with virus one week prior to rust inoculation.

Keywords : Coronadal groundnut. Rust. Puccinia arachidis. Mottle virus. Symptomatology. Disease interaction. Yield and yield components.

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Effect of Butachlor on the Protein Content of C-168 and 1R-36 Rice Cultivars at Different Growth Stages


Author: Lualhati M. Noriel

Abstract

Rice seedlings of C-168 cultivar were markedly inhibited by butachlor up to shoot emergence stage while those of IR-36 showed greater inhibition up to the second leaf stage. Treated rice seedlings up to shoot emergence stage have comparatively less weights than the untreated control in both cultivars. Protein synthesis was severely affected by butachlor treatment at pre-germination up to shoot emergence, the degree of inhibition being greater in IR-36 than in C-168. There was no protein synthesis inhibition when seedlings of both cultivars were treated later during the first and second leaf stages.

Keywords : Rice. Cultivar C-168 and IR-36. Butachlor. Protein content. Different stages of rice plants. Root and shoot elongation.

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Biology of Taro Hornworm, Hippotion celerio L.


Author(s): O. C. E. Diongzon, Jr. and D. P. Gapasin

Abstract

The biology of taro hornworm, Hippotion celerio L., was studied in the laboratory. The eggs were laid singly or in groups on the nether surface of the leaf. Incubation period of eggs was from 3 to 5 days with 97% hatchability. The total developmental period ranged from 29 to 35 days for females and 28 to 35 days for males. It did not differ markedly between the two sexes, but adult longevity was longer in females than in males. Five larval instars were recorded. A male to female ratio of 1.00:1.31 was observed. Of the 6 alternate hosts tested, 4 species were preferred and two species were eaten only under stress of hunger. A hymenopterous parasite, Trichogramma sp., was found infesting the eggs of taro hornworms in the field.

Keywords : Taro. Colocasia esculenta. Taro hornworm. Hippotiorz celerio, Mass rearing. Life history and behavior. Host range. Natural enemies. Trichogramma sp.

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Control of Meloidogyne incognita and Rotylenchulus reniformis and Its Effect on the Yield of Sweet Potato and Cassava


Author: Ruben M. Gapasin

Abstract

Pre-plant treatment of different nematicides, in pot experiments, using the manufacturers’ recommended rates had variable effects on the growth of sweet potato and cassava and on the population of Meloidogyne incognita and Rotylenchulus reniformis 4 months after application. Low gall and egg mass ratings were obtained in chemical-treated plants, except those treated with Hostathion 5G. In all cases, the application of Nemagon 75 E.C. and Temik 15G increased the root, tuber and top weights of sweet potato and cassava and gave from 65-85% reduction in nematode population compared to Furadan 5G and Bunema 40 E.C. which gave from 45-70% reduction. Hostathion 5G was the least effective among the chemicals tested. The application of chicken manure significantly increased roots, tubers and tops of sweet potato and cassava compared to those obtained with nematicides. However, there was no apparent correlation between growth response and per cent control.

Keywords : Nematicides. Chicken manure. Sweet potato. Cassava. Meloidogyne incognita. Rotylenchulus reniformis. Yield. Gall and egg mass rating.

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Integrated Control of the Carmine Spider Mite on Papaya


Author(s): Nelson M. Esguerra and Frank H. Haramoto

Abstract

The potential importance of the western predatory mite, Galendromus occidentalis Nesbitt in the management of the carmine spider mite, Tetranychus cinnabarinus (Boisduval) was evaluated during a 1-year period on papaya trees at Kapaa, Kauai, Hawaii. One summer spray of Vendex at 0.56 kg Al/ha allowed some western predatory mites to survive and it provided adequate control of the carmine spider mite. Also, Vendex was non-phytotoxic to fruit-bearing papaya trees. A combination of malathion and sulfur, which is the standard spray used for mite and insect control on papaya, was found toxic to the predators and its extended and frequent use appears to have caused some pests to develop resistance to this combination. Conversion from a standard program of mite control which uses malathion and sulfur sprays to an integrated control program, utilizing a predator, G. occidentalis and an acaricide, Vender, appears promising.

Keywords : Integrated control. Carmine spider mites. Tetranychus cinnabarinus. Western predatory mite. Galendromus occidentalis. Papaya. Acaricide. Biological control. Hawaii.

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