Increased Pod Yield Research Articles

Influence of Application Variables on Peanut (Arachis hypogaea L.) Response to Prohexadione Calcium

Abstract Prohexadione calcium retards peanut vegetative vine growth, improves row visibility, and potentially reduces pod shed, thus increasing pod yield compared with non-treated peanut. Although prohexadione calcium has been registered for use in peanut for the past decade, practitioners continue to express a range of questions about use including banded application, compatibility with other agrichemcials, and interactions of application rate and timing. In experiments over multiple years, applying prohexadione calcium to lateral branches only of peanut increased row visibility compared with banded applications over main stems or broadcast applications over the entire peanut canopy. Similarly, when using different spray nozzle configurations, greater row visibility was noted when the highest rate of prohexadione calcium was applied over lateral branches compared with broadcast applications of a uniform rate across all spray nozzles or when the highest rate was delivered to main stems. Delaying the first of two sequential applications of prohexadione calcium 1 wk after 50% row closure resulted in reduced row visibility regardless of application rate when compared with sequential applications initiated at 50% row closure. Applying prohexadione calcium within 2 to 3 wks prior to digging and vine inversion resulted in minor increases in improved row visibility and did not affect pod yield. Efficacy of prohexadione calcium was not affected by tank mixing with pyraclostrobin or 2,4-DB.

Role of Insecticides in Reducing Thrips Injury to Plants and Incidence of Tomato Spotted Wilt Virus in Virginia Market-Type Peanut

Tomato spotted wilt virus (family Bunyaviridae, genus Tospovirus, TSWV), transmitted by many thrips species, is a devastating pathogen of peanut, Arachis hypogaea L. TSWV has become a serious problem in the Virginia/Carolina peanut-growing region of the United States. During 2002, TSWV was present in 47% of the North Carolina hectarage and caused a 5% yield reduction in Virginia. Factors influencing levels of TSWV in runner market-type peanut cultivars, which are primarily grown in Alabama, Flordia, Georgia, and Texas, have been integrated into an advisory to help those peanut growers reduce losses. An advisory based on the southeast runner market-type version is currently under development for virginia market-type peanut cultivars that are grown primarily in the Virginia/ Carolina region. A version based on preliminary field experiments was released in 2003. One factor used in both advisories relates to insecticide use to reduce the vector populations and disease incidence. This research elucidated the influence of insecticides on thrips populations, thrips plant injury, incidence of TSWV, and pod yield in virginia market-type peanut. Eight field trials from 2003 to 2005 were conducted at two locations. In-furrow application of aldicarb and phorate resulted in significant levels of thrips control, significant reductions in thrips injury to seedlings, reduced incidence of TSWV, and significant increases in pod yield. Foliar application of acephate after aldicarb or phorate applied in the seed furrow further reduced thrips plant injury and incidence of TSWV and improved yield. These findings will be used to improve the current virginia market-type TSWV advisory.

Effect of pruning on growth, leaf yield and pod yields of okra (Abelmoschus esculentus(L.) Moench)

SUMMARYYoung leaves and pods of okra (Abelmoschus esculentus(L.) Moench) are edible, and so a crop management strategy for removing edible leaves while sustaining good pod yields is required. Pruning treatments were imposed on apically debudded okra plants for 3 years to assess effects of removing a quarter, half or three-quarters of the primary branches on growth and fresh leaf and pod yields. Pruning significantly (P<0·05) delayed fruiting by 8–10 days, extended length of harvest duration by 12–15 days and increased number of pods/plant by 10–40% and pod yield by 9–36% more than the control plants which had neither apical bud removal nor pruning. However, no difference in pod weight or pod length was found between these treatments and the control. Three-quarters pruning significantly (P<0·05) increased fresh leaf yield by 29–49%, but not all the leaves were desirable for consumption because of high fibre content. Decreases were seen in the numbers of secondary branches, shoot dry weight and pod yields (by 40–57, 22–36 and 22–30%, respectively, more than a quarter or half pruning). Although early production of pods in the control plants is often important for early maturity and high market prices, the present study found that a delay in fruiting, an extension in length of harvest duration and an increase in pod yield in plants with a quarter or half pruning enhanced staggered production and maximal pod yield. This helps to ensure a better market price and to enable growers avoid a glut on the market. A direct promotional effect of pruning on pod yields provides a possible strategy for growing okra for both leaf and pod harvests. A quarter or half pruning from the upper parts of the main stems of apically debudded plants to ensure good production and quality of leaves and pods is therefore recommended if okra is to be grown for both leaf and pod yields.

Compatibility of In-Furrow Application of Acephate, Inoculant, and Tebuconazole in Peanut (Arachis hypogaea L.)

Abstract Research was conducted in North Carolina to compare tobacco thrips (Frankliniella fusca Hinds) control, early season peanut emergence and growth, and pod yield with combinations of the insecticide acephate, inoculant containing Brady rhizobium, and the fungicide tebuconazole applied in the seed furrow during planting. Although interactions among treatment factors were significant, greater control of tobacco thrips damage was noted when acephate was applied and in some cases when tebucanozole was applied. Tebucanzole-treated peanut emerged more slowly than peanut not receiving tebucanazole. Delayed emergence of tebuconazole-treated peanut most likely resulted in emergence when fewer tobacco thrips were present in fields. Peanut pod yield was affected by acephate, inoculant, and tebuconazole independently. Applying acephate and inoulcant increased pod yield in two and three of five experiments, respectively. Pod yield was lower in one of five experiments when tebuconazole was applied. These data su...

Response of cowpea, okra and tomato sawdust ash manure

Field experiments were conducted at Akure and Obaile in Southwest Nigeria to test effect of sawdust ash manure treatments on cowpea (var. 1T82D – 716), okra (var. NAAe – 47 – 4) and Roma variety of tomato. The nutrient analysis of leaf and pod of okra given by different sawdust ash manure treatments was done. Sawdust ash manure applied at 4t/ha increased growth and yield parameters of cowpea. Sawdust ash applied at 3 to 12 t\\ha increased pod yield of Okra and 9t/ha sawdust ash was optimum. Sawdust ash applied at 3, 6 and 9t/ha increased Okra leaf and pod P, K, Ca and Mg contents. Sawdust ash manure increased number and weight of tomato fruits significantly. Relative to control, 2, 4, 6 and 8 t/ha ash increased number of tomato fruits by 109, 226, 265 and 226% respectively, and the equivalent values for fruit weight were 29, 55, 64 and 57%. The 4t/ha sawdust ash is recommended for cowpea and tomato. Key words: Sawdust ash; nutrient; soil; crops Moor Journal of Agricultural Research Vol.4(2) 2003: 178-182

Cassava Cultivation Management for Sustainable Vegetable Production in Intercropping with Okra

ABSTRACT A five-year field experiment evaluated the effects of growing okra [Abelmoschus esculentus (L.) Moench] in inter-row spaces of cassava (Manihot esculenta Crantz) and at three sowing dates on yield of both crops. Two contrasting cassava cultivars (TMS 30572-early maturing, short with full-branch and dense canopy and Odongbo-late maturing, tall with less-branch and sparse canopy) were evaluated. In the first experiment, okra was sown on 30 July, 20 August and 3 September as a late-season crop in 1999 and on 27 May, 10 June and 24 June as an early-season crop in 2000. In the second experiment, okra was sown on 29 May, 21 June and 12 July as an early-season crop in 2001 and on 13 August, 29 August and 12 September as a late-season crop in 2002. Leaf area index (LAI), days to 50% flowering and first pod harvest, yield and yield components of okra in mixed stands were the same as in monoculture in both experiments. However, cassava Odongbo/okra intercrop resulted in an increase in fresh pod yield and economic returns of okra by 19-21% and 20-26%, respectively, compared with monoculture and cassava TMS 30572/okra intercrop. LAI of okra was significantly increased by 20-45% in the first and second sowing dates, but it took 2-10 days longer for the first and second-sown okra plants to reach 50% flowering and first pod harvest over those of the third-sowing date in any experiment. Mean increase in okra fresh pod yield with first and second sowing dates was 2.4-5.6 tha−1 over the third sowing date in either experiment. The mean economic returns with the first and second sowing dates were 105% and 50% in the first experiment and 125% and 50% in the second experiment, respectively, over those of the third sowing date regardless of cropping system. The cassava yields were not affected by cropping system and okra sowing date. For sustainable okra production in wide inter-row spaces of cassava, growing both crops in May for the early-season crops and in early August for the late-season crops and using tall, sparse canopy cassava is recommended.

Integrated applications of aqueous leaf extract ofDatura meteland chlorothalonil improved control of late leaf spot and rust of groundnut

Late leaf spot (LLS) (causal agent Phaeoisariopsis personata) and rust (causal agent Puccinia arachidis) are economically important foliar diseases of groundnut (Arachis hypogaea) and have global significance. Aqueous leaf extracts of Datura metel and Lawsonia inermis, known for their high antifungal activity against P. personata, completely inhibited the germination of urediniospores of P. arachidis in vitro. In the greenhouse, extracts of D. metel (25g/L) and L. inermis (50g/L) applied as a prophylactic spray reduced the frequency of LLS lesions and rust pustules by 65–74% compared with controls. In field studies, a programme of four sprays of D. metel leaf extract at 45, 60, 75 and 90 days after sowing (DAS) was partially effective against the foliar diseases (LLS and rust) up to 95 DAS. A single spray of chlorothalonil at 45 DAS combined with three sprays of D. metel at 60, 75 and 90 DAS effectively reduced the combined severity of LLS and rust. The increase in pod yield by this treatment (91 % over control) was comparable with the sustained application of chlorothalonil. Further validation of integrated applications of D. metel extract and chlorothalonil may reduce the dependency on fungicides in groundnut cultivation.

Peanut Response to Inoculation and Nitrogen Fertilizer

Experiments were conducted from 2000 through 2003 in North Carolina to compare peanut (Arachis hypogaea L.) response to inoculation with Bradyrhizobium In one study that included 20 experiments, peanut pod yield was compared following no inoculation or inoculation with commercial granular or liquid in‐furrow products. In six of these experiments, inoculant was also applied to the seed before planting. In six other experiments within this study, pod yield of inoculated and noninoculated peanut was determined following surface applications of N approximately 40 d after planting. In a second study, peanut pod yield was compared in twin row planting patterns (two rows spaced 18 cm apart on 91‐cm centers) when inoculant was applied in‐furrow to one of the twin rows or to both of the twin rows. In a third study, interactions of in‐furrow inoculation and fumigation with metam sodium were compared. Peanut pod yield was higher following inoculation in 7 of 20 experiments. In six of the seven experiments where a yield response to inoculation was observed, peanut had not been planted previously in these fields. In experiments where peanut responded positively to inoculant, pod yield was higher when inoculant was applied in the seed furrow rather than to seed before planting. Nitrogen increased pod yield linearly in three of six experiments (p ≤ 0.05). Inoculating both rows of peanut seeded in twin row patterns yielded higher in two of four experiments than when one of the twin rows was inoculated or when inoculant was not included. Fumigation with metam sodium did not affect pod yield, regardless of inoculation treatment.

Influence of Two Insecticides, Chlorpyrifos and Quinalphos, on Arginine Ammonification and Mineralizable Nitrogen in Two Tropical Soil Types

Effects of seed treatments with chlorpyrifos [5 g of active ingredient (ai) kg(-1) of seed] and quinalphos (6.25 g of ai kg(-1) of seed) and standing crop treatments with chlorpyrifos (800 g of ai ha(-1)) and quinalphos (1000 g of ai ha(-1)) on arginine deamination and mineralizable nitrogen were monitored, in the sandy loam and loamy sand soils of two tropical semiarid fields, for three consecutive crop seasons. The arginine ammonification activity of rhizospheric microbes was inhibited after seed treatment with chlorpyrifos and quinalphos and their principal metabolites, 3,5,6-trichloro-2-pyridinol (TCP) and 3,5,6-trichloro-2-methoxypyridine (TMP) and 2-hydroxyquinoxaline and quinoxaline-2-thiol, respectively. Quinalphos produced transient inhibitions, whereas chlorpyrifos and its metabolites (TCP and TMP) exerted a greater inhibition in both loamy sand and sandy loam soils. Arginine ammonification by nonrhizospheric microbes was stimulated by standing crop treatments with both pesticides. In the loamy sand soil, the parent compounds stimulated rhizospheric N-mineralization, whereas the metabolites were inhibitory. However, nonrhizospheric N-mineralization was inhibited by both chlorpyrifos and quinalphos and stimulated by their metabolites. A higher magnitude of inhibition of arginine deamination in the loamy sand than in the sandy loam soil could be due to greater bioavailability of the pesticides in the former, resulting from lesser sorption of the pesticides due to alkalinity of the soil and its low content of clay and organic carbon. Although both pesticides affected mineralizable nitrogen, seed treatment with quinalphos and standing crop treatment with quinalphos and chlorpyrifos produced the most significant effects. The recommended doses of the pesticides not only efficiently controlled whitegrubs, which increased pod yields, but also left no residues in harvested kernels. They also caused no long-term inhibition of ammonification, which could have been of significant concern during the short crop period in semiarid areas where nitrogen determines plant productivity.

Effects of Brassmosteroids on Growth, Nodulation, Phytohormone Content and Nitrogenase Activity in French Bean Under Water Stress

Effect of pre-treatments of 1 and 5 μM epibrassinolide or homobrassinolide prior to water stress induction on changes in root nodulation and contents of endogenous abscisic acid (ABA) and cytokinin trans-zeatin riboside (ZR), and nitrogenase activity was investigated in the nodulated roots of Phaseolus vulgaris L. cv. Arka Suvidha. Brassinosteroids in the unstressed plants increased root nodulation, ZR content and nitrogenase activity, and also ameliorated their stress-induced decline in the nodulated roots. The ABA contents in the nodules of control or stressed plants were not altered by brassinosteroids treatment. There was an increase in pod yield by brassinosteroids treatment (5 μM) in the irrigated control as well as stressed plants without influencing pod number or pod length. Among the brassinosteroids, epibrassinolide was relatively more effective.

Peanut (Arachis hypogaea L.) Response to Cyclanilide and Prohexadione Calcium

Abstract Excessive growth of Virginia market-type peanut affects row visibility and pod yield of peanut. Ten experiments were conducted from 2000 to 2002 in North Carolina to compare peanut response to cyclanilide and prohexadione calcium applied at 50% row closure followed by a repeat application 2 wk later. Cyclanilide and prohexadione calcium increased row visibility in all experiments. Main stem height was shorter at the end of the season when cyclanilide and prohexadione calcium were applied compared with non-treated peanut in all experiments except one. Prohexadione calcium improved row visibility compared with cyclanilide in three experiments and equaled cyclanilide in seven experiments. Main stem height was similar following application of cyclanilide and prohexadione calcium in eight of the 10 experiments. When pooled over experiments, pod yield ranged from 4210 to 4480 kg/ha and did not differ between non-treated peanut and peanut treated with either plant growth regulator. However, prohexadione calcium did increase pod yield of peanut compared with cyclanilide. Results indicate that cyclanilide is not as effective as prohexadione calcium in managing peanut vine growth because of inconsistent enhancement of row visibility and possible negative impacts on pod yield.

Rhizobia and AM Fungal Inoculation Improve Growth and Nutrient Uptake of Bean Plants Under Organic Fertilization

ABSTRACT Potted bean (Phaseolus vulgaris L. cv speed wonder) plants were grown in a glasshouse with and without organic and chemical fertilizers, un-inoculated or inoculated with rhizobia (a mixed culture of Rhizobium leguminosarum bv. phaseoli and R. tropici) and arbuscular mycorrhizal fungi (AMF) (Glomus spp.), singly or in combination. Treatment effects on growth, nodulation, AMF colonization and nutrient uptake of plants were evaluated. Rhizobial inoculation positively influenced root dry weight and nodulation of plants. Shoot and root dry weights and nodulation were again higher in dually inoculated plants compared to singly inoculated plants. Compared to control, single inoculation either with rhizobia or AMF did not increase pod yield. But, dual inoculation significantly increased pod yield compared to control or singly inoculated plants. Inoculation also significantly increased pod yield in organic fertilization treatment, but not in chemical fertilization treatment. AMF colonization, spore population and shoot N and P were also significantly higher in dually inoculated plants. Under fertilized conditions, nodulation, AMF colonization and spore population were generally more pronounced in dually inoculated organic plants than in chemical plants. Shoot Ca, and K remained unaffected by inoculation either in fertilized or unfertilized conditions. Dual inoculation significantly increased the concentration of shoot Mg in organic plants, but not in chemical. In general, better positive effects of inoculations were observed in organic plants than in chemical suggesting higher dependency of organic plants on these symbionts for better growth and development.

Response of Strip-Tilled Peanut to Broiler Litter, Starter Fertilizers, and Fungicide in an Irrigated Cropping System

Abstract Peanut (Arachis hypogaea L.) production in the Southern Coastal Plain of the U.S. is being impacted by increased use of broiler litter and by conservation tillage. There are no studies on the use of broiler litter for peanut grown in strip tillage and very little information on the use of starter fertilizers. Runner-type peanut was included in a 3 yr, double-cropped, irrigated rotation to determine the effects of broiler litter rates and starter fertilizers on disease development, pod yield, market grade, and gross economic value of runner market type peanut. Broiler litter rates of 0, 4.5, 9.0, and 13.5 Mg/ha were applied to the soil surface without incorporation prior to seeding. Within each broiler litter rate there were three starter fertilizer regimes (none, 93 L10–34–0/ha, and 93 L 12–22–5/ha) each with and without flutolanil {N-[3-(1-methylethoxy) phenyl]-2-(trifluoromethyl) benzamide}applied twice at 1.12 kg ai/ha/application. Over 4 yr, broiler Utter either decreased or did not affect pod yield, market grade, or gross economic value of peanut. Southern stem rot (Sclerotium rolfsii) incidence was not affected by broiler litter, but Rhizotonia limb rot (Rhizoctonia solani, AG-4) incidence increased with broiler litter rate, possibly accounting for some of the decreases in production variables. Broiler litter application was neither an agronomic nor economic best management practice for peanut in this strip-tilled study. Flutolanil increased pod yield, market grade, and gross economic value of peanut regardless of broiler litter rate by decreasing the incidence of southern stem rot and Rhizotonia limb rot. Starter fertilizer had little effect on any of the measured parameters.

Integrated nutrient management in rainy season groundnut (Arachis hypogaea)

A field experiment was conducted at Berhampur during rainy ( kharif) season of 2003 and 2004 on loamy sand soil to study the effect of integrated use of FYM, recommended dose of fertilizer (RDF) i.e. 20-17.4-33.3 kg N-P-K/ha, Rhizobium, gypsum (250 kg/ha) and boron (1 kg/ha) on performance of groundnut ( Arachis hypogaea L.) and soil fertility. Results revealed that application of FYM + 75% RDF + Rhizobium + gypsum + boron re- corded significantly higher pods/plant, 100 pod weight resulting in higher pod (2.66 tonne/ha), kernel yield (1.92 tonne/ha) and nutrient uptake (151.4-17.0-58.6-0.8-0.07 kg N-P-K-S-B/ha). This treatment also had generated maximum net return (Rs. 22,000/ha). The increase in pod yield of this treatment was 65 and 14% higher over

Effect of irrigation scheduling, conjunctive use of water sources and fertilizer levels on yield and water productivity of groundnut (Arachis hypogaea)

A field experiment was conducted for 2 consecutive years 200809 and 200910 at Deras, Mendhasal, Odisha, to study the effect of conjunctive use of water sources and fertilizer levels on yield and water use of winter (rabi) season groundnut (Arachis hypogaea L.). The treatments included 3 levels of conjunctive use of water [C 1 (2 irrigations through canal water only, C 2 irrigations with canal water + 1 irrigation with ground water and C 2 2 3 irrigations with canal and 2 irrigations with ground water)] and 5 fertilizer treatments, [(F , no NPK; F , 100% NPK 0 1 (20, 40 and 40 kg/ha as N, P O and K O), F , sugarcane trash bio-compost (STBC) alone (1 t/ha); F , 75% NPK + 2 5 2 2 3 sugarcane trash bio-compost (0.25 t/ha) and F , 50% NPK+ sugarcane trash bio-compost (0.50 t/ha)]. Pod and 4 haulm yields of groundnut were significantly increased with conjunctive-use of water sources (ground and canal water) compared to canal water irrigation alone. The increase in pod yield was 45.3% and haulm yield 40.3% with conjunctive use of 2 irrigations through canal and 2 irrigations through ground water over 2 irrigations with canal water. This treatment also gave the maximum gross returns ( 47,714/ha), net returns ( 35,166/ha) and benefit: cost ratio (2.80). With application of 75% NPK + STBC (0.25 t/ha) 70.3% and 73.4% increase in pod and haulm yields was observed compared to the control (no fertilizer application). The highest water use (434 mm), water-use efficiency (5.06 kg/ha-mm) and benefit: cost ratio (3.11) were recorded with application of 75% NPK + STBC (0.25 t/ha).

Response of rainy-season groundnut (Arachis hypogaea) to varying fertility levels and bioformulations

An experiment was conducted during the rainy (kharif) season of 2017 at Gwalior, Madhya Pradesh, to study the response of groundnut (Arachis hypogaea L.) to biofertilizers and inorganic sources of nutrient. The experi- ment consisting of 4 fertility levels, viz. 25% recommended dose of fertilizer (RDF), 50% RDF, 75% RDF and RDF allotted to main plots, and 3 bioformulations, viz. no bio-formulations, NPK liquid formulation + Zn-solubilizing bac- teria and bio-grow allotted to subplots, was laid out in split-plot design with 3 replications. Results showed that an application of RDF resulted in significantly highest number of branches/plant, number of nodules/plant and dry- matter accumulation at 30, 60 and 90 days after sowing (DAS). Increasing dose of fertilizers up to RDF resulted in significant increase in haulm, pod yield and net returns. Among the bioformulations, seed inoculation with liquid bio NPK formulation with Zn solubilizing bacteria and bio-grow significantly increased the haulm, pod yield and net re- turns by 9.8, 8.6, 14.5% and 8.0, 4.3, 7.2%, respectively, over no bioformulation application. Besides, all growth at- tributes, pod yield and net returns were significantly influenced with combined application of liquid NPK + Zn-solu- bilizing bacteria and RDF. The integrated application of RDF with liquid NPK formulation + Zn-solubilizing bacteria ensured the highest pod yield followed by RDF application with bio-grow.

Effect of conjunctive use of phosphorus and bio organics on growth and yield of groundnut (Arachis hypogaea)

A field experiment was conducted during the rainy season of 2000 and 2001, to study the effect of conjunctive use of phosphorus and bio organics on groundnut (Arachis hypogaea L.). Application of 60 kg P,O,/ha markedly influenced the growth and yield attributes resulting in significant increase of pod yield by 14.01% over the control. Seed inoculation with Rhizobium or phosphorus solubilizing micro organism (PSM) marginally improved yield, but their combined use increased pod yield significantly. Both the organics, i.e. FYM and need cake, significantly in creased the pod and haulm yields, but when half quantity of these organics were integrated with Rhizobium and PSM, the highest pod yield of 31.80 qtha with FYM 5 tonnestha Rhizobium PSM was obtained. Neem cake 1.5 tonneslha in the presence of same biofertilizers was next to it.

Farmers' participatory integrated management of foliar diseases of groundnut

Late leaf spot (LLS) caused by Phaeoisariopsis personata [(Berk and Curt) v. Arx = Cercosporidium personatum (Berk. & Curt.) Deighton] and rust caused by Puccinia arachidis (Speg.) are the two most destructive fungal foliar diseases of groundnut worldwide. Together, these two diseases can cause more than 50% yield loss in groundnut in many countries. Foliar disease management in groundnut often involves indiscriminate use of chemicals or total reliance on host plant resistance (HPR). On-station experiments on integrated disease management (IDM) at ICRISAT-Patancheru, India, have clearly demonstrated that when moderate levels of HPR are combined with seed treatment and affordable levels of chemical control, expected yields and economic returns are higher than obtained with chemical control of susceptible genotypes. We evaluated the performance of this combination in on-farm farmer-participatory research. The groundnut genotypes were ICGV 89104, ICGV 91114, TMV 2 and a local cultivar. Thirty farmers from Anantapur, Kurnool, and Nalgonda districts in the state of Andhra Pradesh, India, conducted the experiments during the 1995 and 1996 rainy seasons. Local agronomic practices were followed. Experiments were conducted under both high disease pressure [nonintegrated disease management (non-IDM) i.e. natural] and low disease pressure [integrated disease management (IDM), i.e. seed treatment and fungicide, chlorothalonil sprayed once at 60 days after sowing, d.a.s.]. The severities of LLS and rust on test genotypes were significantly lower than on TMV 2 and the local cultivar up to 65 d.a.s. The increase in pod yield over the local cultivar and TMV 2 in IDM plots was 60% in ICGV 89104, and 55% in ICGV 91114. Farmers preferred these two genotypes because of their close phenotypic similarity to the local cultivar. Our studies also suggest that any technology developed for groundnut should offer a clear yield and foliar disease resistance advantage over farmers' current practices.

POD YIELD AND KERNEL SIZE DISTRIBUTION OF PEANUT PRODUCED USING SUBSURFACE DRIP IRRIGATION

Longterm yield data are essential to determine the economic feasibility of installing a subsurface drip irrigation(SDI) system for crop production. However, first year yields and associated economic returns are vital for system paymentthe first year. Vegetable and row crop production has been successful with SDI, but pod yield and kernel size distribution dataon peanut (Arachis hypogaea L.) are limited especially during the installation year. Site 1 was established in 1997 on aFaceville sandy loam soil (fine, kaolinitic, thermic Typic Kandiudults) converted from native grass pasture. Site 2 wasestablished in 1998 on a Tifton sandy loam soil (fineloamy, kaolinitic, thermic Plinthic Kandiudults) following two yearsof cotton. These SDI systems include two lateral spacings (0.91 and 1.83 m) buried at 0.3 m soil depth. Site 1 had two emitterspacings (46 and 61 cm) and two irrigation levels. Site 2 had one emitter spacing (46 cm) and three irrigation levels. Anonirrigated (NI) control was included at each site. Irrigation water was applied daily based on estimated ETo whereirrigation level one (IL1) was ETo *Kc, and IL2 and IL3 were 75 and 50% of IL1, respectively. Pod yield increased 38% withSDI (5433 kg ha 1 ) compared to NI peanut (3937 kg ha 1 ). When compared to the state average (3012 kg ha 1 ), SDI showeda 81% pod yield increase. The percentage of jumbo kernels increased 39% at Site 1 and 81% at Site 2 compared with NI. SDIpeanut had lower quantity (75% less) of number one sized peanut kernels than NI. Overall, during the installation year, SDIhad higher pod yields and larger kernel size than NI treatments. These yield data can be useful when projecting the economicfeasibility of installing a SDI system and making the first year payment.

Rational Use of Fungicide Applications to Maximize Peanut Yield Under Foliar Disease Pressure in West Africa.

Foliar diseases caused by Cercospora arachidicola, Cercosporium personatum, and Puccinia arachidis are major constraints to peanut production in the world. Fungicides are among the most efficient available control methods. Field trials were conducted in 1991 and 1992 in Benin and Niger, West Africa, to evaluate the cost effectiveness of fungicide application timings and frequencies on four peanut cultivars. A combination of four timings (40, 55, 70, and 85 days after sowing) was scheduled. Early (causal organism, C. arachidicola) and late (caused by C. personatum) leaf spot were prevalent in both years, but late leaf spot was the more economically important disease as shown by high values of area under the disease progress curve. Application of fungicide reduced late leaf spot incidence and increased pod yield. Pod yield responded to an interaction of number and timing of fungicide applications. With appropriate timing two or three fungicide applications were enough to significantly increase pod yield. Properly timed fungicide sprays can result in substantial monetary gains for peanut farmers in West Africa.