Effects Of Drip Irrigation Regimes Research Articles

Effect of Drip Irrigation Regimes and Mulching on Cucumber Production under Cooled Plastic Tunnel Conditions, Kassala State, Sudan

An experiment was conducted in a cooled plastic tunnel greenhouse during March-August of 2022 and 2023, the objectives of this study to investigate the effect of drip irrigation regimes and mulching on yield and yield components of cucumber under greenhouse conditions, Kassala, Sudan. Seedlings of the most popular cucumber hybrid (Fatin) were planted on 40cm and 50 cm inter and intra-row spacing, respectively. The experiment was composed of two factors; the irrigation regimes (75%, 100% and 125% of recommended irrigation water) and the other was mulching (mulching and no mulching). These factors were arranged in split plot design with three replications. The main plots were allocated for irrigation regimes and subplots for mulching. The subplot size was 200cm×70cm (bed/mastaba). Results reported that125% of recommended irrigation water (RIW) under drip irrigation recorded highest yield and yield components in both seasons. Moreover, the highest values of yield and yield components; fruit length, fruit diameter and fruit weight were obtained under 125% of (RIW) with mulch while, the lowest were obtained with75% of (RIW) without mulch on both seasons. The highest values of water productivity and economic water productivity were recorded under 125% of (RIW) with mulch. On the other hands, the highest marginal rate return (MRR) was obtained under 100% of (RIW) with no mulch.

Особенности формирования саженцев малины при капельном орошении в условиях дерново-подзолистых почв Центрального Нечерноземья

Practically no studies on drip irrigation of raspberries in the conditions of the Moscow region have been carried out, in particular, the patterns of the production process of plants under drip irrigation have not been identified. In this regard, the purpose of the research was to study the effect of drip irrigation regimes on the formation of raspberry seedlings in the conditions of soddy-podzolic soils in the Central region of the Non-Chernozem zone of Russia. The studies were carried out on the lands of the educational and experimental farm of the laboratory of fruit growing "Michurinskiy Sad" of the Russian State Agrarian University - Moscow Timiryazev Agricultural Academy in 2020-2022. The two-factor field experience included regimes as the first factor, and varietal characteristics as the second. As a result of the research, it was revealed that drip irrigation contributes to the saving of irrigation water and the creation of an optimal water-air regime of the soil during the entire growing season. In the variant of drip irrigation with maintaining moisture in the root layer in the range of 80-100% of the lowest moisture capacity, the saving of irrigation water compared to furrow irrigation averaged 65%, and in the variant of 60-80% of the lowest moisture capacity - 78%. Drip irrigation contributes to the formation of seedlings with the highest values of biometric indicators (stem diameter, plant height, leaf surface area and volume, length, mass of the root system) and increase productivity. An analysis of the experimental data on the biometric indicators of raspberries and its yield allows us to recommend irrigation regimes with maintaining the moisture content of the root layer of the soil in the range of 70-90% of the lowest moisture capacity and 80-100% of the lowest moisture capacity as optimal.

Effect of drip irrigation regimes on growth, yield and economics of maize (Zea mays) genotypes

A field experiment was conducted during summer 2018 and 2019 to study the performance of maize (Zea mays L.) genotypes under drip and furrow irrigation regimes at the Main Agriculture Research Station, University of Agricultural Sciences, Dharwad, Karnataka. The experiment was laid out in strip plot design with 3 replications. Treatments included 4 irrigation levels (drip irrigation at 0.6 ETc, 0.8 ETc and 1.0 ETc and furrow irrigation at 0.8 IW/CPE ratio) and 4 maize genotypes. The data indicated that, furrow irrigation at 0.8 IW/CPE ratio and drip irrigation at 1.0 ETc recorded significantly higher and on par growth and yield parameters, grain yield (75.8 q/ha and 71.4 q/ha, respectively) and economic returns. Drip irrigation at 1.0 ETc consumed 28.6% less water but recorded significantly higher water productivity over furrow irrigation. Among the genotypes, NK-6240 found superior over rest of the genotypes. The combination of furrow irrigation with NK-6240 recorded significantly higher growth and yield attributes as well as grain yield and economics over rest of the combinations. However, this treatment remained statistically non-significant with drip irrigation at 1.0 ETc with NK-6240 and furrow irrigation with CP-818.

Evaluation of fertigation and drip irirgation on growh, yield and quality parameters of bhendi [Abelmoschus esculentus (L.) Moench

Field experiments were carried out during the Kharif season in 2008 and 2009 at Eastern block farm, Tamil Nadu Agricultural University, Coimbatore, to find out Effect of drip irrigation regimes and fertigation levels on plant growth, yield parameters, quality parameters and water use efficiency of bhendi. The treatment includes two irrigation regimes in main plot and eight fertigation levels in sub plot and replicated thrice. Drip irrigation at 100% PE resulted in higher yield parameters of bhendi viz., fruit length, fruit weight and fruit girth and also significantly higher fruit yield of bhendi (13,606 kg/ha) followed by irrigation at 75% PE (12,454 kg/ha). Drip fertigation at 150% RDF with P through water soluble fertilizer registered significantly higher fruit yield (14,434 and 14,711 kg/ha during 2008 and 2009, respectively). The crude protein, crude fibre, ascorbic acid and mucilage of bhendi was significantly higher under irrigation regime of 100 and fertigation at 150% RDF with P as WSF. In both the years, drip irrigation resulted in considerable saving of irrigation water besides enhancing WUE. Highest net return was realized in bhendi with M2S8 (Drip irrigation at 100% PE with fertigation level of 150% RDF with P as WSF) recorded a net return of Rs.2, 60,082. However, the B: C ratio was higher with drip irrigation at 100% PE along with fertigation schedule of 75% RDF with P as basal (12.88).

Effect of drip irrigation regimes and mineral fertilizer rates on watermelon yield in mulched fields

Crop growth in arid and semiarid regions usually depends on irrigation, but inappropriate irrigation practice can result in water stress. Water needs of watermelon are the highest during the period of strong formation of vegetative and generative organs. Thus, 85-90% moisture is required from seeds for seed germination. Before the formation of fruit, soil moisture should be maintained at 70% of the total field moisture capacity of the soil, and at the time of fruit ripening at 60%. In this article, the results of experiments based on the development of optimal irrigation regime and fertilization rate for the cultivation of watermelon plants in mulched fields by drip irrigation method, differentiated soil moisture (60...70...60%, 65...75...65%, 70...80...70%, 75...85...75% SAM (SAM - Soil available moisture)), and fertilization rates (without fertilizer, N100P80K40, N120P100K50 and N140P120K60 kg/ha) have been written. Also, the effect of fertilization rates (N100P80K40, N120P100K50 and N140P120K60 kg/ha) on the quality indicators of watermelon fruit, the amount of dry matter, sugar, nitrates and “C” in the fruit has been noted.

Effect of drip irrigation regimes and nitrogen levels on growth, yield and economics of aerobic rice (Oryza sativa L.)

Water supply to agriculture especially rice will be affected in the future because of climate change and increased demand of water for non-agricultural use. To sustain rice production, focus should be on water saving rice production systems such as aerobic rice, which may further reduce water requirement when combined with drip irrigation. Hence, a field experiment to study the influence of drip irrigation regimes and nitrogen levels on growth, yield and economics of aerobic rice was conducted at Tirupati, Andhra Pradesh, during the rabi seasons of 2019-20 and 2020-21. Four main plot treatments consisting of irrigation regimes based on pan evaporation i.e., drip irrigation at 1.25 Epan, 1.50 Epan, 1.75 Epan, 2.00 Epan and four sub plot treatments comprising of four doses of nitrogen i.e., 75 % RDN (90 kg N ha-1), 100 % RDN (120 kg N ha-1), 125 % RDN (150 kg N ha-1) and 150 % RDN (180 kg N ha-1) were tested in split plot design replicated thrice. Significantly higher plant height, number of tillers, yield attributes, grain yield, straw yield and gross returns were recorded with drip irrigation regime of 2.0 Epan over other irrigation regimes, but was comparable with drip irrigation at 1.75 Epan. While, higher net returns and B:C ratio were recorded with drip irrigation regime of 1.75 Epan which was at par with 2.0 Epan and 1.5 Epan. Aerobic rice grown with 180 kg N ha-1 proved to be superior with respect to plant height, number of tillers m-2, panicle weight, grain yield, straw yield, gross returns and net returns which was however comparable with 150 kg N ha-1 in case of panicle number, filled grains per panicle, test weight and B:C ratio. Among the interaction combinations, drip irrigation regime of 2.0 Epan along with 180 kg N ha-1 resulted in superior plant height, tillers m-2, yield attributes, grain yield, straw yield, gross returns, net returns and B:C ratio which was statistically at par with drip irrigation regime of 1.75 Epan along with 180 kg N ha-1 except in case of tiller number.

Effects of drip irrigation regimes on growth, quality plum seedlings, and water use efficiency in European Russia

Currently, there is a lack of capacity in Russia nursery breeding, as a result of which a significant part of the planting material comes from abroad. Drip irrigation is one of the types of resource-saving technologies that make it possible to intensify agricultural production, including in the field of growing planting material for horticulture. The results of the experiment show that for a more rational use of irrigation water and obtaining high-quality planting material of plums in the nursery, it is recommended to use an irrigation regime with maintaining soil moisture in the range of 70-90 and 80-100% of the lowest moisture capacity with a soaking depth in the first year of 30 cm, for the second year - 40 cm, and in the third year - 50 cm. With this irrigation regime, the maximum development of seedlings, their quality and quantity are observed.

Interactive Effects of Nitrogen and Drip Irrigation Rates on Root Development of Corn (Zea Mays L.) and Residual Soil Moisture

Deficiencies in water and nitrogen (N) can lead to poor crop growth and production. This study was carried out during 2012–2014 to determine (1) the effect of drip irrigation regimes and N fertilizer rates on root length density (RLD) of corn (Zea mays L. cv. Single cross 704) and soil moisture dynamics and (2) the relationship between root development and water availability. The experiment was arranged into a split-plot design with three irrigation regimes as the main factor (I1 = 60, I2 = 80, and I3 = 100% evapotranspiration [ETc]) and five levels of N fertilizer (N1 = 0, N2 = 50, N3 = 100, N4 = 150 and N5 = 200 kg/ha) as the subfactor. The combination I1N4 produced the highest grain yield and yield components while I3N5 gave the lowest performance. The highest RLD was recorded at full irrigation water requirement and it increased with increasing N rate, but not in a linear trend, as higher N rates showed less effect. Nitrogen application under drip irrigation increased the RLD in soil depending on irrigation level. Soil moisture was optimized at full irrigation water requirement and 150 kg/ha N.

Effects of Drip Irrigation Regimes Under Plastic Film on Sugar Beet Yield and Water Use Efficiency in Xinjiang

Abstract. This 2-yr study analyzed the effects of different irrigation regimes of drip irrigation under plastic film on sugar beet production in Xinjiang, China, and established a binary quadratic regression equation and normalization to describe the maximum root yield, sugar yield, and water use efficiency. Three irrigation frequencies (10, 11, and 12 d) and two irrigation water quotas (45 and 60 mm) were combined to form six treatments. Irrigation frequency had a significant effect on root yield at 1% level of significance in both years, but the effects on sugar yield and water use efficiency were nonsignificant. In both years, the sugar yield resulting from 60 mm irrigation water quota at frequency of 11 d increased by 10.8% and 6.5%, respectively, compared with that resulting from 45 mm irrigation water quota at frequency of 11 d. The regression equation based on the experimental observations indicated that in Xinjiang the optimal irrigation regime was 11 d and 55 mm which saved 21.2% irrigation water for the highest sugar beet yield. The data optimization to determine the weight of roots and evapotranspiration found that root growth exhibited a pattern similar to the aboveground crop growth, and the root growth was most rapid in the period 30 July to 10 August. Keywords: Irrigation frequency, Irrigation water quota, Optimal irrigation regime, Root growth, Root yield, Sugar yield, Water use efficiency.

EFFECT OF WATER DEFICIT ON THE GROWTH, YIELD AND ESSENTIAL OIL CONTENT OF LEMONGRASS IN VIVO.

Two field experiments were carried out on Cymbopogon citratus, during two years of 2015 and 2016 at Al Khtatbah, Sadat Center, Minufiya Governorate, Egypt. The aim of this research work was to study the effect of drip irrigation regimes (24, 12, 8 and 4 liters/plant/week) on yield and essential oil content of lemongrass. All growth and yield characters were significantly affected by the deficit of irrigation water. The plant height, number of tillers, fresh and dry weights / plant, fresh and dry yield per hectare) as well as nutrient content in the dry herb, essential oil percentage and oil yield of lemongrass decreased as affected by water deficit in all cuts of the two experimental seasons. However, the highest irrigation regime (24 liters/plant/week) provided the best results in this respect. On the other hand, the best quality of the essential oil (concentration of citral) was obtained at the lower regime (8 liters /plant/week).

Effects of drip-irrigation regimes with saline water on pepper productivity and soil salinity under greenhouse conditions

The aim of this study was to investigate the response of sweet pepper (Capsicum annuum L.) to saline irrigation water and various irrigation regimes. The experiments were conducted in a greenhouse with two sweet pepper varieties (ONUR F1 and ADA F1) over two cropping seasons: spring and autumn on the Mediterranean coast at Antalya, Turkey. The irrigation regimes comprised four levels of Class A pan-evaporation and were applied using a drip irrigation system when evaporation reached a target value of around 10mm. These four levels represented 0.50, 0.75, 1.00 and 1.25 of Class A pan-evaporation. In each irrigation regime the sweet pepper plants were exposed to four salinity treatments with electrical conductivities of 1.0, 2.5, 3.5 and 6.0dSm−1 respectively. The study showed that both pepper varieties generally performed in a similar manner (except in terms of vegetative biomass production). The amount of salt accumulation within the root-zone was higher in spring compared to autumn; and therefore related to the total amount of irrigated water usage between seasons due to climatic variability. Increased salinity induced higher levels of salt accumulation within the pepper plant’s root-zone, while an increased amount of saline irrigation water increased the size of the affected layer within the root-zone. Overall, an increased level of salinity alongside increased irrigation considerably depressed both vegetative growth and yield. Higher irrigation water productivities were attained with a regime comprising 0.50 of Class A pan-evaporation and which appeared to fulfil crop water requirements. It was found that sweet pepper varieties ONUR F1 and ADA F1 are moderately sensitive to salinity with a threshold value of 1.43dSm−1 and a decreasing slope value of 11.1%. Although both seasons revealed a single salinity response function, there were considerable differences in the actual fresh pepper yield. This study demonstrates that for pepper crops irrigated with saline water (or grown on salt-affected soils), pepper growers must consider the salinity response function and seasonal productivity alongside an appropriate irrigation regime.

Effect of drip fertigation on growth, seed and root yield of ashwagandha [Withania somnifera (L.) Dunal

An experiment was conducted during 2005–06 and 2006–07 winter seasons to study the effect of drip irrigation regimes and fertility levels on physiological parameters, growth and yield of ashwagandha (Withania somnifera L. Dunal). The treatments consisted of three irrigation regimes, viz., I1: drip irrigation at 100 % pan evaporation (PE), I2: drip irrigation at 80 % PE and I3: drip irrigation at 60 % PE, combined with three fertility levels, i.e., F1: 100 %, F2: 75 % and F3: 50 % of recommended dose of NPK, control having surface irrigation and soil application of fertilizers. The cultivation of ashwagandha with application of drip irrigation at 80 % of pan evaporation along with application of 100 % recommended dose through fertigation resulted in significant improvement in growth, physiological parameters such as crop growth rate, relative growth rate, net assimilation rate, leaf area index, chlorophyll content, and root and seed yields.

Effects of drip irrigation regimes on potato tuber yield and quality

To evaluate the effects of drip irrigation regimes on potato (Solanum tuberosum L.) tuber yield and quality, an experiment was conducted in 2009 and 2010. Experimental factors were the irrigation regimes including: FI, providing 100% of the water requirement of potato; IR1, providing 70% of the water requirement of potato by reducing the applied irrigation water between planting and tuber initiation by 30%; and IR2, providing 70% of the water requirement of potato by reducing the applied irrigation water during the whole growing season by 30%; and three potato cultivars Agria, Almera and Sinora. The results indicated that cultivars Agria and Almera were much better than Sinora in terms of tuber yield under all irrigation regimes. For Agria and Almera, the experiments show that the full irrigation regime had the highest yield and water productivity. For Sinora, however, deficit irrigation yields higher water productivity than the full irrigation regime. Consequently, deficit irrigation IR1 and IR2 should be applied to Sinora, but not to Agria and Almera.

Drip fertigation impact on yield and alkaloid content ofWithania somnifera(L.) Dunal

An experiment was conducted to study the effect of drip irrigation regimes and fertigation levels on performance of Withania somnifera (L.) Dunal (Ashwagandha). The treatments included three irrigation regimes and three fertility levels with a control treatment having surface (furrow) irrigation and soil application of fertilizer. Maximum root yield of 795 kg/ha and seed yield of 78 kg/ha was obtained with irrigation at 80% PE followed by 100% PE and 60% PE. Application of full dose of fertilizer (100% RD) produced maximum quantity of roots (745 kg/ha), which was 4.9% and 12.9% more than that of 75% (710 kg/ha) and 50% RD (660 kg/ha). The maximum alkaloid content in the roots was obtained with drip irrigation (0.52%).

Effects of drip irrigation regimes and basin irrigation on Nagpur mandarin agronomical and physiological performance

The scarcity of irrigation water is one of the major causes of low productivity and decline of citrus orchards. The present study was planned with a hypothesis that the drip irrigation (DI) could save a substantial amount of water over surface irrigation, besides improving the yield of citrus plants. The experiment was conducted for 3 seasons during 2006–2009, with ‘Nagpur’ mandarin (Citrus reticulata Blanco) plants budded on rough lemon (Citrus Jambhiri Lush) rootstock in central India. The effects of DI and basin irrigation (BI) on soil chemical properties and crop responses were studied. DI was scheduled every-other-day at 40%, 60%, 80% and 100% of the alternate day cumulative evaporation (Ecp) measured in Class-A evaporation pan. DI except irrigation at 40% Ecp proved superior to BI, producing more growth and fruit yield of plants. The higher plant growth was recorded with higher regime of DI. The maximum fruit yield in DI at 80% Ecp, using 29% less irrigation water resulted in 111% improvement in irrigation water productivity under this treatment over BI. The heavier fruits, with lower acidity and higher total soluble solids, were harvested in DI at 80% Ecp compared with BI. The significant variation of soil water content at 0–0.2 m depth under DI indicated the confinement of effective root zone of the plants in top 0.2 m soil. The maximum rate of net-photosynthesis, stomatal conductance and transpiration in leafs was recorded in DI at 100% Ecp. However, the plants under DI at 80% Ecp exhibited the highest leaf water use efficiency. The maximum salinity build-up with highest decrease in pH was observed in 0–0.2 m soil under DI, whereas the salinity development was prominent in 0.4–0.6 m soil with an increase in pH under BI. The gain in available macronutrients (N, P and K) and loss of micronutrients (Fe, Mn, Cu and Zn) in soil followed the similar trend of EC. The leaf nutrient (N, P, K, Fe, Mn, Cu and Zn) analysis revealed that DI produced significantly (P < 0.05) higher concentration of macronutrients in leafs than that with basin-irrigated plants. However, the effect of irrigation on micronutrients in leafs was statistically insignificant. Overall, these results reveal that the application of optimum quantity of water through DI (80% Ecp) could impose desirable water stress on ‘Nagpur’ mandarin plants, improving their yield and fruit quality, without producing the higher vegetative growth.

Effects of drip irrigation regimes on potato tuber yield and quality under plastic mulch in arid Northwestern China

Field experiments were conducted to study the effects of drip irrigation regimes on potato ( Solanum tuberosum L.) growth, tuber yield and quality, and water use efficiency (WUE) when grown under plastic mulch in an arid area of Northwestern China in 2008, 2009 and 2010. The 2008 experiment consisted of a drip irrigation check without plastic mulch and four different drip irrigation frequency treatments with plastic mulch: once every day, once every 2 days, once every 4 days, and once every 8 days. In 2009 and 2010 the drip check treatment without mulch was irrigated at −25 kPa soil matric potential (SMP) during three potato development stages and four different SMP drip irrigation strategies were compared during the potato development stages (using plastic mulch): S1 (−25 kPa SMP during the three development stages), S2 (−25 kPa SMP during tuber initiation and bulking and −35 kPa SMP during maturation), S3 (−25 kPa SMP during tuber initiation and maturation and −35 kPa SMP during bulking), S4 (−35 kPa SMP during the three development stages). Plastic mulch negatively affected tuber yield, WUE, and tuber quality. In the presence of plastic mulch, tuber yield, specific gravity, starch content, and vitamin C content seemed to be enhanced as the irrigation frequency increased, although the differences were not statistically significant. Irrigation frequency did not affect WUE for potato grown under plastic mulch. Analysis of plant height, tuber yield and WUE showed that a drip irrigation threshold of −35 kPa SMP led to obvious water stress for potato growth in this arid area. Under plastic mulch in 2010, S2 was the optimum drip irrigation regime because of the significantly higher yield than S3 and S4, the highest WUE and significantly firmer tubers than any of the other irrigation regimes tested.

Effect of drip irrigation regimes on yield and quality of field grown bell pepper

This study examined the effects of different irrigation regimes on yield and water use of bell pepper ( Capsicum annuum sp. 1 1-B-14) irrigated with a drip irrigation system under field conditions in 2002 and 2003 growing seasons in the Mediterranean region of Turkey. Irrigation regimes consisted of three irrigation intervals based on three levels of cumulative pan evaporation (Epan) values ( I 1, 18–22 mm; I 2, 38–42 mm; and I 3, 58–62 mm); irrigations occurred on the respective treatments when Epan reached target values. Three plant-pan coefficients were evaluated as irrigation levels ( K cp1 = 0.50, K cp2 = 0.75 and K cp3 = 1.00). Irrigation intervals varied from 3 to 6 days in I 1, 6 to 11 days in I 2 and 9 to 15 days in I 3 treatments. Combined variance analysis indicated that experimental years were not significantly different, but both K cp and irrigation intervals ( I) significantly influenced total pepper yields. Maximum and minimum yields were obtained from the I 1 K cp3 and I 3 K cp1 treatments: 33,140 kg ha −1 and 21,620 kg ha −1 in the first experimental year and 35,298 kg ha −1 and 21,010 kg ha −1 in the second experimental year, respectively. As the K cp value decreased the total yields within each irrigation interval also decreased. However, with the lower irrigation frequency ( I 3), lower yields were obtained with all K cp coefficients. Crop evapotranspiration (ET) values in the treatments varied from 365 mm in I 2 K cp1 to 528 mm in I 1 K cp3 in the first experimental year and 309 mm in I 3 K cp1 to 511 mm in I 1 K cp3 in the second experimental year. Significant second degree polynomial relations were found between pepper yield and total water use for each irrigation interval in 2002 and 2003 growing seasons. Different irrigation intervals resulted in similar water use in the treatments with the same K cp value. Water use efficiency (WUE) and irrigation water use efficiency (IWUE) values were significantly influenced by the irrigation intervals, plant-pan coefficients and experimental years ( Y 1: 2002 and Y 2: 2003) at 1% level of significance. WUE ranged from 4.7 kg m −3 in I 3 K cp2 to 7.6 kg m −3 of ET in the I 1 K cp1 in the 2002 growing season and ranged from 6.4 kg m −3 in I 3 K cp3 to 7.9 kg m −3 of ET in the I 2 K cp2 in the 2003 growing season. Maximum IWUE was observed in Y 1 I 1 K cp1 (7.7 kg m −3), and minimum IWUE was in Y 1 I 3 K cp3 treatment (4.8 kg m −3) in the experimental years. K cp coefficients (irrigation amounts) and irrigation frequencies ( I) and years had significantly different effects on quality parameters such as the first and second quality yield, and number of fruit. Both K cp and I significantly influenced the mean fruit weight, pepper length and width, as well as stem diameter and plant height at harvest. In conclusion, I 1 K cp3 irrigation regime is recommended for field grown bell pepper in order to attain higher yields with improved quality.

Effect of fertigation on stevia (Stevia rebaudiana) under drip irrigation

A field experiment was conducted at the Directorate of Water Management, Bhubaneswar (Odisha) during rabi seasons of 2005-06 and 2006-07 to study the effect of drip irrigation regimes and fertigation levels on stevia (Stevia rebaudiana, Bertoni), grown in rice fallow. The treatments included three irrigation regimes (I - drip irriga- 1 tion at 100% PE, I at 80% PE and I at 60% PE) and three fertility levels (F -100%, F 75% and F - 50% recom- 2 3 1 2 3 mended dose of 110-45-45 kg N-P O -K O/ha) with an extra treatment as control having surface irrigation with soil 2 5 2 application of fertilizers were tested in a factorial randomized block design with three replications. Pooled data of two years showed that drip fertigation improved fresh leaf by 4.9 %, dry leaf by 4.0 % and total biomass yield by 2.04 % over conventional surface irrigation with soil application of fertilizer. Irrigation through drip at 100% PE pro- duced maximum fresh leaf (8.95 t/ha), dry leaf (2.74 t/ha) and total biomass yield (34.44 t/ha). Application of 100% RD (F ) gave highest quantity of fresh leaf (8.21 t/ha), dry leaf (2.53 t/ha) and biomass (33.50 t/ha) compared to 1 75% RD and 50% RD. Application of irrigation at 100% PE with 100% recommended dose of fertilizer produced 9.13 t of fresh leaf 2.90 t dry leaf and 35.0 t biomass yield per hectare and; improved glycoside contents. However, the magnitude of N, P and K contents in both soils and plants have also been enhanced with 100% fertilizer appli- cation of N, P O and K O (110-45-45 kg/ha) compared to lower levels. 2 5 2

Effects of drip irrigation scheduling on muskmelon yield and quality

The use of drip (trickle) irrigation for muskmelon ( Cucumis melo L.) production has become commonplace but the impact of preharvest drip irrigation management on fruit yield and quality has not been well documented. The effects of drip irrigation regimes on the yield and quality of cv. Challenger, Mission and Vera Cruz were investigated at Davis, California in 1993 and 1994. All plots were irrigated uniformly until 10 days (1993) or 20 days (1994) before harvest; differential treatments were then imposed, ranging from a complete cutoff of irrigation to full irrigation (applied daily) through the harvest period. Fruit quality (firmness, seed cavity and mesocarp condition and soluble solids content) was evaluated at harvest, and after 7 or 14 days of refrigerated storage at 4 °C or 2 °C in 1993 and 1994, respectively. Drip irrigation management did not affect marketable yield, fruit size or % cull fruit. All irrigation treatments produced high quality fruit of equal soluble solids content. There were significant cultivar effects on both yield and quality, but no cultivar × irrigation interactions were noted. In this environment late-season irrigation was not detrimental to muskmelon quality but was not required for maximum productivity.