Row Strips Research Articles

Optimizing water use between intercropped pea and maize through strip row ratio expansion and N fertilizer reduction in arid areas

• Expending strip row ratio reduced soil evaporation but increased evapotranspiration. • Higher strip row ratio and lower N rate reduced water competition of pea relative to maize in co-growth period. • Water compensation of maize from pea strips was improved through strip row ratio expansion and N fertilizer reduction. • Water complementary use boosted grain yield and enhanced water productivity of maize/pea intercropping. Water is the primary limiting factor for crop production in the semi-arid regions. It is imperative to improve water productivity in these water-limited areas. In this research, a field experiment, at Hexi Corridor of northwestern China from 2009 to 2011, was conducted to explore whether changing of strip row ratio and N fertilizer rate will affect water use in maize ( Zea mays L.)/pea ( Pisum sativum L.) intercropping. Two strip row ratios (i.e. 2 rows of maize and 4 rows of pea, designated as I1; and 3 rows of maize and 4 rows of pea, designated as I2) and three N fertilizer rates (i.e. 0 kg N ha −1 , designated as N0; 90 and 300 kg N ha −1 for pea and maize, designated as N1; and 135 and 450 kg N ha −1 for the two crops, designated as N2) were employed in this research. The results showed that I2 improved LAI and reduced soil evaporation across whole growth period, but increased total evapotranspiration by 8.9 % compared to I1. In co-growth period, water competition in I2 was reduced by 19.3 % compared to I1. While in maize independent growth period, water compensation in I2 was improved by 17.2 % compared to I1. For N fertilizer effect, water compensation with N1 and N2 was improved by 16.2 % and 21.1 % compared to N0. The mixed grain yield with I2 was improved by 20.3 % compared to I1; and that with N1 and N2 was improved by 44.0 % and 42.8 % compared to N0. As a result, I2 improved water productivity by 10.5 % compared to I1; and N1 and N2 improved it by 43.8 % and 42.5 % compared to N0, respectively. We concluded that expanding strip row ratio coupled with lower N fertilization could improve water productivity of maize/pea strip intercropping, which is promising in arid areas to save water and achieve the sustainable development goals.

English

Potassium-nutrition is a subject of great consideration, as research has revealed its importance in increasing sugar recovery in sugarcane. While it cannot achieve its genetic expression of yield without proper planting technology. Therefore, the present study was conducted to optimize the planting method and K level to improve the yield and sugar recovery of sugarcane at University of Agriculture Faisalabad in 2014-2016. Treatments comprised of four planting methods viz. i) 90 cm spaced pits with a diameter of 90 cm, ii) 90 cm spaced pits with a diameter of 90 cm in diagonal fashion, iii) 90 cm spaced double row strips and iv) 120 cm spaced trench planting in combination with four K nutrition levels i.e., 0, 100, 200 and 300 kg/ha K2O. Results revealed that K application improved the growth, cane yield and sugar recovery irrespective of planting method. However, maximum number of tillers were recorded in sugarcane sown in diagonal pit planting at 90 cm with 100 kg/ha K2O. Likewise, Leaf area index and net assimilation rate were substantially improved with K application in all planting methods. More cane weight (15%) was obtained at sugarcane sown in 120 cm spaced trenches with 200 kg/ha K2O during both the years. Stripped cane yield was maximum in diagonal pit planting at 90 cm with 100 kg/ha K2O (113.7 t/ha) during the plant crop year and diagonal pit plantation + 200 kg/ha K2O (98.22 t/ha) during the ratoon crop year. Likewise, maximum potassium use efficiency (KUE) i.e. 99.5 and 88.2 kg /kg were recorded in planting of sugarcane in diagonal pits at 90 cm with 100 kg/ha K2O during plant crop year and 120 cm trenches +100 kg/ha K2O during the ratoon crop year, respectively. Sugar recovery was also enhanced by all the K nutrition levels over control. The cultivation of sugarcane in 90 cm spaced pits with the supplementation of potash at 100 kg/ha gave the maximum sugar yield of 15.8 t/ha in plant crop year and 13.2 t/ha in the ratoon crop year. The combined economic analysis over two years (plant + ratoon year) revealed that sugarcane planting was more beneficial at 120 cm spaced trenches, with 100 kg potash/ha (3678$); which was followed by 90 cm diagonal pit plantation +100 kg/ha K2O which gave the combined benefits of 3611$. Sugar cane may be planted in 90 cm diagonal pits and 120 cm spaced trenches with 100 kg/ha potash to improve the cane yield and sugar recovery

The Use of Different Cropping Systems for Pepper (Capsicum Annum) Seed Production in Tropical Rain Forest Soils of Nigeria

A cropping system that involved the use of intercropping and planting patterns was used to test the profitability of producing pepper seeds. The triple replicated randomized complete block design experiment was carried out during the wet and dry seasons of 2018 at the Teaching and Research Soils of the Rivers State University Port Harcourt. The planting patterns were: Sole pepper (control), strip rows, double alternate rows and scattered pattern while maize and okra were used as inter crops. During the wet and dry seasons, the control (sole pattern) outperformed the other patterns in fresh pepper fruit yield (6000kg/ha, 5503kg/ha) but not in fruit number and fruit seed yield which were not significantly different from that of strip rows. Also, the strip rows fresh maize cobs yield (9573.3kg/ha, 6133.33kg/ha) and okro pods yield (2453kg/ha, 2470.67kg/ha) in wet and dry seasons respectively were high. With Land equivalent ratio of 2.3 and 1.62 in both seasons, the strip row pattern proved to be more stable, sustainable and profitable. This cropping system (pepper, maize and okra inter crop on strip row pattern) is therefore very profitable since it allows poor resource farmers to harvest different crop produce (maize cobs and okro pods) for use and sale until the maturation, processing and sale/use of the pepper seeds.

Intercropping Agricultural Practices by Improving Maize Early Growth Process: A Bio-Statistical Approach

Fertile soil pressure represents a crucial concern vis-a-vis of agricultural crop yield improvement in several southern countries. Environmental concerns and soil low fertility as well as a rapid demographic development and as well intensive industrial exploitation with regard ground resource, drastically contribute in reducing agricultural land availability. We believe that multiple culture and/or intercropping experimentation designs, integration in southern countries agricultural practices, could partially overcame fertile soil pressure issues. The main types of intercropping include mixed intercropping, row intercropping and strip intercropping. Here we assessed maize/cowpea intercropping patterns as well as maize monoculture systems. For this purpose, experimental dispositive is as following; 5 parcels including sole maize plants, 5 parcels with alternation of maize and cowpea plots on the same row (strip intercropping) and 5 parcels including maize and cowpea alternation rows (row intercropping), by a computational statistical approach with the purpose to promote mixed crops practices in contrasting fertile soil availability concerns, optimizing maize plants growth process. Growth data (plant height and plant leave number) apropos 52 maize plants for each above described experimental sites were collected during 9 weeks and processed by own R script, including descriptive and analytical statistical surveys. Findings clearly shown a positive impact of intercropping practices in accelerating maize early growth process. Maize and cowpea rows intercropping exhibited a good performance in term of accelerating maize growth process as opposite to maize monoculture (p<0.03) and maize/cowpea strip intercropping parcels (p<0.001). This study highlighted the usefulness mixed cultures intercropping system based on maize/cowpea rows alternation planting pattern in improving maize early development and as well promoted experimental design as a valuable solution in agronomical research for contrasting agricultural concerns vis-a-vis of limited productive and as well low fertile ground resources.

Laboratory evaluation of dynamic behavior of steel-strip mechanically stabilized earth walls

To investigate the influence of the peak acceleration, the loading duration, and the strip length on the dynamic behavior of steel-strip reinforced soil walls (SSWs), in terms of the dynamic reinforcement load distribution and the dynamic lateral earth pressure behind the surface, a series of 1-g shaking table tests was performed on five reduced-scale reinforced soil wall models. It was observed that the maximum axial force of the strips (Tmax) is mobilized at the intersection of the failure plane with strips in all rows. It was also discovered that, in the upper half of the walls, the Tmax values decrease with a decreasing strip length, while this trend is reversed in the lower half of the walls. Additionally, a proper convergence was found between the Tmax/H·γs·SV·SH and L/H′ ratio at different levels of acceleration and duration, so that Tmax/H·γs·SV·SH can be defined as a function of the L/H′ ratio and the seismic parameters for different rows of strips. On the other hand, it was observed that the values of earth pressure predicted by conventional methods under static and seismic conditions are too conservative and these methods predict the position of the resultant lateral force higher than the actual point.

Efficacy of Anaerobic Soil Disinfestation for Control of Prunus Replant Disease.

Prunus replant disease (PRD) is an important soilborne complex that suppresses growth and productivity of replanted stone fruit and nut orchards. It is effectively managed with preplant soil fumigation but, due to regulatory challenges, nonfumigant-based control strategies for PRD and other soilborne disease problems may become increasingly important, especially in California. We examined the potential of preplant anaerobic soil disinfestation (ASD) for control of PRD in four repeated orchard replant trials on sandy loam soil near Parlier, CA. After removal of the old orchard trees, alternative ASD treatments, all using rice bran as the main carbon source, were implemented, starting in late September. The alternative treatments incorporated rice bran at (i) 20 t ha-1, alone, in 3.0-m-wide row strips; (ii) 20 t ha-1, preceded by incorporation of a sudangrass cover crop and followed by drip application of molasses (10 t ha-1), in 3.0-m-wide row strips; (iii) 20 t ha-1, alone, in 1.8-m-wide strips; or (iv) 12 t ha-1, alone, in 1.8-m-wide strips. All ASD-treated areas were covered with clear tarp and drip irrigated with 25 cm of water. Tarps remained for 6 weeks, during which the soil moisture level was kept at or above field capacity by drip irrigation. All trials included nontreated control and fumigated standard treatments. ASD raised temperature and reduced redox potential in soil at 15- and 46-cm depths for 6 weeks. Fumigation and ASD treatments both nearly eradicated bioassay inoculum of Pythium ultimum in the soil before almond trees were replanted and significantly affected almond tree root communities of fungi and oomycetes after planting. Fumigation treatments and ASD treatments with rice bran at 20 t ha-1 in 3.0-m strips increased tree growth significantly and by similar magnitudes. Among repeated experiments, mean increases in trunk cross-sectional area growth due to fumigation ranged from 137 to 264%, while the increases due to ASD at 20 t ha-1 in 3.0-m strips ranged from 148 to 214%, compared with controls. ASD offers effective control of PRD and is worthy of further optimization and testing for management of PRD and additional orchard replant problems.

Design, development and field evaluation of row-cleaners for strip tillage in conservation farming

Given the drawbacks of conventional soil tillage and direct drilling, an environmentally friendly technology of strip-tillage has been gaining increasing popularity worldwide because it allows the employment of full tillage and direct drilling advantages. Strip-tillage compared to the direct drilling is a good option for proper seedbed preparation because it ensures favourable conditions for seed germination; in comparison with full tillage it reduces working time, fuel and production costs, protects soil, and is environmentally friendly. To remove plant residues from a tilled soil strip row, cleaners of different shapes are used. There is a lack of knowledge regarding which design and technological parameters of the row cleaners of strip-tillage equipment are best suited for interaction with soil and plant residues. Therefore, theoretical research of 340mm serrated disc row cleaners was carried out, which substantiated the strip width while assessing the disc rake angle, gap between the centres of row cleaner disc fixing holders (gap Blc) and working speed. The experimental research was carried out in the Trial Station of Aleksandras Stulginskis University; it established the influence of different technological parameters of row cleaners on the distance of wheat residue removal. The experimental research established that the serrated disc row cleaners of a strip-tillage machine cleans the greatest amount of plant residues; when the rake angle of the cleaner discs varies from 10° to 15°, gap Blc is 165–180mm, and the working speed ranges from 1.3ms1 to 2.5ms1.

Results from 13-year study of cultivar-rootstock combinations in sweet cherry

The study was carried out during the period 1999-2011 at the Institute of Agriculture - Kyustendil, Bulgaria. The growth, reproductive characteristics and fruit quality of 'Van' sweet cherry trees, grafted on clonal rootstocks: 'P-7', 'Karamy', 'Hybrid 2', 'SL-64' and seedlings from 'Vladimir' and 'Mahaleb 20-86' were studied. The trees on 'SL-64' were used as a control. The trees were planted in the spring of 1999 at distances of 5.50×5.0 m, formed in free-growing crowns and grown without irrigation. After thirteen years, the biggest trunk cross-sectional area had the trees grafted on 'Hybrid 2' and the smallest on 'Mahaleb 20-86'. The trees crown volume was reduced by 14.9% for 'Vladimir', 21.4% for 'P-7', 22.6% for 'Hybrid 2', 27.8% for 'Mahaleb 20-86', and 35.9% for 'Karamy', when compared to 'SL-64'. The row strips were not occupied by the trees, which allow optimizing planting distances. 'P-7' had the highest root-suckering ability, followed by 'Vladimir'. Trees grafted on 'Vladimir' had the best vitality, while those on 'Karamy' were with the highest mortality rate. The highest productivity had the trees on 'SL-64' and the lowest on 'Karamy'. Productivity was also good for 'P-7' and 'Vladimir', which was confirmed by the data for yield efficiency and the quantity of fruit 1 m-3 of the crown volume. No significant differences were found in the average weight and fruit size as well as in their chemical composition (dry matter, total sugars and acids) among tested rootstocks.

High productivity of wheat intercropped with maize is associated with plant architectural responses

Mixed cultivation of crops often results in increased production per unit land area, but the underlying mechanisms are poorly understood. Plants in intercrops grow differently from plants in single crops; however, no study has shown the association between plant plastic responses and the yield advantage. Here, we assessed the productivity of wheat-maize intercropping as compared to sole wheat and sole maize, and the associated differences in wheat shoot and leaf traits. In two field experiments, intercrop wheat and maize were both grown in alternating strips consisting of six rows of wheat and two rows of maize. The traits of wheat plants in border rows of the strips were compared to the traits of plants in the inner rows as well as those in sole wheat. Leaf development, chlorophyll concentration and azimuth, as well as the final leaf and ear sizes, tiller dynamics of wheat and yield components of both crops were determined. The relative densities of wheat and maize in the intercrop were 0.33 and 0.67, respectively, but the corresponding relative yields compared to the respective monocultures were 0.46 for wheat and 0.77 for maize. Compared to wheat plants in the inner rows of the intercrop strips as well as in the monoculture, border-row wheat plants in the intercrop strips had (a) more tillers owing to increased tiller production and survival, and thus more ears, (b) larger top leaves on the main stem and tillers, (c) higher chlorophyll concentration in leaves, (d) greater number of kernels per ear and (e) smaller thousand-grain weight. Grain yield per metre row length of border-row wheat was 141% higher than the sole wheat, and was 176% higher than the inner-row wheat. The results demonstrate the importance of plasticity in architectural traits for yield advantage in multispecies cropping systems.

Optimizing Row Spacing to Ameliorate the Productivity of Spring Sugarcane (&amp;lt;i&amp;gt;Saccharum officinarum&amp;lt;/i&amp;gt; L.)

One of the main reasons behind reduced cane yield is pathetic method of planting. Planting method and row spacing are the most important yield contributing factors in sugarcane. A field experiment was carried out in order to determine quality and yield of sugarcane in various spatial arrangements. Treatments are 180 cm spaced trenches with triple row strips; 180 cm spaced trenches with alternate row strips; 120 cm spaced trenches with double row strips and 60 cm spaced furrow with single row. Perusal of data revealed that 3.6%, 13.4%, 15%, 15.3% more cane diameter (cm), cane length (cm), stripped cane yield (t·haˉ1), sugar yield (t·haˉ1) were obtained from 180 cm spaced trenches with triple row strips as compared to conventional planting method i.e. 60 cm spaced furrows. While the number of millable canes mˉ2, polarity %, cane juice purity %, cane juice %, commercial cane sugar % and cane sugar recovery % remained non-significant by different planting techniques.

COMPETITION BETWEEN APPLE-TREES AND GRASS IN THE ORCHARD

The objective of the research was to study the possible competition between roots of apple-trees and grass under the influence of applied moisture regulation methods. No analogical research has been performed in Latvia so far. The investigation was done on the base of an existing trial planted in 1997 with cultivar `Melba` at 1.5 × 4 m planting distances. Three different treatments of soil moisture management were compared: control, sawdust mulch and fertigation. Inter-row strips were covered by grass vegetation (Lolium perenne and Poa pratensis, in proportion 1:3). The horizontal and vertical spacing of the main root mass was determined, as well as the distance and depth of the spread of grass roots from the inter- row strip into the tree strip. The results of the research show that mulching and fertigation have significant influence on the horizontal and vertical root spacing of grass grown in the inter-row strip, which can be an evidence of competition between apple-trees and grass for water and nutrients.

No-till strip row farming using yearly maize-soybean rotation increases yield of maize by 75 %

Development of agronomic practices that maximize the use of natural resources to improve soil health and crop productivity is critical for long-term sustainability of agricultural technologies. In Ontario, Canada, the most conventional maize production practice follows a 3-year rotation with soybeans and ploughing of the land before planting and after harvesting. This technology yields 8–10 t ha−1 of maize. We became aware of a long-term no-till strip row farming system developed by an Ontario grower where maize yields are double that of the average for the province. This study set out to identify what factors contribute to such a massive yield increase and the basis for this superior method of maize production. In a 2-year field study, we compared a variety of biotic and abiotic factors associated with yields at this highly productive site with those of two average yielding sites. The no-till strip row farming system grew maize and soybeans in alternate strips rotated yearly and had higher plant populations, better root architecture, higher plant biomass, and 75 % greater (18.35 t ha−1) grain yield compared to a nearby farm that used conventional production practices. About 21 % of the yield increase resulted from early planting, greater number of seeds planted, and healthier ears/seeds. The remaining 54 % increase was linked to larger ears, which we tentatively attribute to beneficial effects conferred by the microorganisms that develop in this unique agro-ecosystem. The average net return at the no-till site was estimated to be CDN (Canadian) $2000 ha−1, which was 400 % higher than the net returns of the conventional sites. The study concludes that no-till management where soil remains undisturbed when combined with yearly rotations of an appropriate legume crop, growing crops exactly on the same cropping rows every year, and optimization of plant density creates a sustainable technology for maximizing maize yields.

Studies on Productivity and Performance of Spring Sugarcane Sown in Different Planting Configurations

Row spacing has a pivotal role in enhancing sugarcane yield and improving its quality. A study was undertaken to evaluate the influence of different planting techniques on performance of sugarcane at Agronomic Research Area, Department of Agronomy, University of Agriculture Faisalabad during Kharif 2014. Experimental treatments comprised of: 180 cm spaced trenches with tripple row strips, 180 cm spaced trenches with alternate row strips, 120 cm spaced trenches with double row strips and 60 cm spaced furrows with single rows. Sugarcane cultivar HSF-240 was used as experimental material. The experimental was conducted in RCBD with four replications. The expeimental results revealed that sugarcane number of tillers, plant height, cane length, stripped cane weight and stripped cane yield increased progressively with the increase in row spacing from 60 to 180 cm. While germination percentage and number of millable canes were not affected by different sowing techniques, maximum number of tillers (15.96 m-2), plant height (333.25 cm), stripped cane weight (0.94 kg) and stripped cane yield (107 t·ha-1) were recorded from 180 cm spaced trenches with tripple row strips.

The effect of intercropping pattern of okra, maize, pepper on weeds infestations and okra yield

Field study was conducted to evaluate the efficacy of intercropping pattern in reducing weed infestation in okra, maize and pepper intercrop; at the teaching and research farm of Rivers State University of Science and Technology Port Harcourt, Nigeria during 2009 and 2010 cropping season. Three intercropping pattern namely; alternate row intercropping, strip row intercropping and mixed intercropping were compared to sole cropping in a randomized complete block design replicated three times. The result reveal that weed biomass were significantly lower in both years in all forms of intercropping pattern compared to sole cropping or mono-cropping. Weed smothering efficiency in both years showed that mixed pattern (45.7%) >alternate row pattern (33.4%) > strip row pattern (11.5%). Crop yield were better in an intercrop system for maize and pepper in both years compared to sole crop. However, mean okra fruit yield was highest in sole cropping (3253 kg ha-1) when compared to intercropping pattern. Maize yield was highest in mixed pattern (8,987 kg ha-1) and lowest in sole cropping (6,955 kg ha-1) while pepper fruit yield was highest in strip row pattern (5,435 kg ha-1) and lowest in mixed pattern (1,562 kg ha-1). The results from this study have shown that intercropping pattern has a great potential in reducing weed infestation in cropping systems especially in farming system with low external input. However, the effect of the intercrop pattern on yield may be variable, because viability may depend on the adaptation of planting pattern and selection of compatible crops. Key words: Intercropping pattern, weed infestation, land equivalent ratio (LER).

Diverse Irrigation Levels with Planting Patterns and Its Effect on Yield of Maize (Zea Mays L.)

To study the effect of diverse irrigation levels viz. 0, 3, 4, 5 and 6 irrigations and two planting patterns viz.60 cm apart single rows and 30/90 cm apart double row strips (30 cm from row to row and 90 cm from strip to strip) on growth and yield of maize, a field trial was carried. Number of plants per plot at harvest, number of grains per cob, 1000 grain weight, biological yield, grain yield and harvest index were significantly affected by different irrigation levels but the growth and yield of maize were not influenced by Planting patterns. When 6 irrigations and planting spacing was kept at 30/90 cm apart; double row strips (30 cm from row to row and 90 cm from row to row), maximum grain yield (7.28 t ha -1 ) was produced.

Agro-Economic Evaluation of Various Maize Hybrids Under Different Planting Patterns

Abstract An experiment was carried out at the Agronomic Research Area, University of Agriculture, Faisalabad to assess the agro-economic performance of two maize hybrids (SIPRA-4444 and TS- 13) under five different sowing patterns viz. ridge sowing 60 cm apart rows, bed sowing 60 cm apart rows, 60 cm apart single row strips, 90 cm apart double row strips and 120 cm apart triple row strips. The results indicated that the hybrids and the sowing patterns had a significant influence on the grain yield of maize. SIPRA-4444 produced maximum grain yield (6.02 tha-1) as compared to TS-13 (5.80 tha-1). Among the planting methods, ridge sowing produced highest grain yield (7.13 t ha-1). The interactive effect of hybrids and sowing methods showed that the hybrid SIPRA - 4444 produced maximum yield when it was sown on 60 cm apart ridges. From economic point of view, maximum net income of Rs. 114172 and benefit to cost ratio of (2.37) was obtained when the hybrid SIPRA-4444 was sown on 60 cm spaced ridges.

Impact of soil moisture depletions, planting geometry and soil texture on bio economic efficiency of autumn sugarcane under arid conditions

Abstract In arid areas of central Pakistan application of 2800 and 2200 mm irrigation water in 28 and 22 irrigations on sandy loam and silty soils, respectively to autumn sugarcane through flooding is a common practice. Whether this irrigation depth and frequency is sufficient to fulfill the requirements of autumn sugarcane is not established. This study was conducted to evaluate the optimum water requirements by applying direct method of soil water measurement through gravimetric procedure. A three years field study was conducted on autumn sugarcane cv. HSF 240 at research area of MLL (Main Line Lower) Land Reclamation Research Station Chak No. 37 TDA (Thal Development Authority) Bhakkar, Pakistan on sandy loam and Gomal University Dera Ismail Khan Pakistan on silty clay soil from 2003–04 to 2005–06. The experiment was laid out in randomized complete block design with factorial arrangement in four replications and net plot size was 24 m 2 . The four available soil moisture depletion levels under study were ASMDL 1 (20%), ASMDL 2 (40%), ASMDL 3 (60%) and ASMDL 4 (80%) and four planting patterns G 1 (60 cm), G 2 (75 cm) spaced single row planting patterns, G 3 (30/90 cm) and G 4 (30/120 cm) spaced paired row strip planting patterns were tested. The analysis of three years pooled data showed that maximum shoot dry weight, sugar yield, water use efficiency and benefit cost ratio were recorded in the treatment interaction of ASMDL 2 (40%) × G 3 (30/90 cm) followed by ASMDL 2 (40%) × G 2 (75 cm), ASMDL 2 (40%) × G 1 (60 cm), respectively, whereas minimum in the interaction of ASMDL 4 (80%) × G 4 (30/120 cm) at both soils. Maximum sugar recovery percentage (10.87 and 10.78%) was recorded in ASMDL 4 (80%) × G 4 (30/120 cm) planting pattern and minimum values of 8.44 and 7.28% on sandy loam and silty clay soils, respectively was recorded in ASMDL 1 (20%) × G 1 (60 cm) planting pattern. It was concluded that irrigation application on the basis of direct method of soil water measurement through gravimetric procedure saved 15.56 and 10.29% irrigation water by applying 38 and 23 irrigations keeping the depth of each irrigation 54 and 74 mm on sandy loam and silty clay soils, respectively as compared with traditional method of irrigating autumn sugar cane crop through flooding under arid conditions. Therefore maximum bio economic benefits could be obtained from autumn sugarcane crop by irrigating it at 40% ASMDL and sowing in 30/90 cm spaced paired row strips in arid conditions on sandy loam and silty clay soils.

Impact of different levels of non-Bt cotton refuges on pest populations, bollworm damage, and Bt cotton production

The impact of structured strip row refugia (varying from 10% to 50%) in the Bt cotton crops JKCH1947Bt (producing one toxin, Cry1Ac) and MRC7017BGII (producing two toxins, Cry1Ac and Cry2Ab) on the pest complex and cotton yield was studied. During the cropping season (June 2008 to November 2008), sucking pest incidence was negligible. However, the incidences of spotted bollworm, Earias vittella, and the leafroller, Sylepta derogata, were high on the non-Bt cotton. The total cotton seed yield of the Bt crop plus the refuge decreased proportionately with respect to the increase in proportion of non-Bt cotton. Total cotton production decreased significantly when 40% non-Bt cotton was planted as refuge. These studies showed that a refuge of up to 30% non-Bt cotton in JKCH1947Bt and up to 20% non-Bt cotton in MRC7017Bt did not affect total seed cotton yield compared to 100% Bt cotton.

HERBIGATION IN A CHERRY ORCHARD – EFFICIENCY OF PENDIMETHALIN

HERBIGATION IN A CHERRY ORCHARD – EFFICIENCY OF PENDIMETHALIN

Landsat Coverage of the Earth at High Latitudes

Overlapping coverage of Landsat imagery at high latitudes is examined systematically and quantitatively. The Earth is separated into “row strips” aligned with the Landsat World Reference System (WRS), and the multi-scene coverage of Landsat imagery is divided into three types of areas: extended, missing, and overlap. Varying image orientation and narrowing row-strip width with increasing latitude are shown to have major impacts on these three areas. The dependencies of these coverage areas on skipping image collections from adjacent paths are calculated. This forms the basis for sampling strategies that can significantly reduce the number of images required to obtain full ground coverage at high latitudes. The calculations show that Antarctica can be covered with approximately one-third the total number of scene opportunities.