Screening of germplasm for specific traits is a continuous pre-breeding process in deriving the drought-tolerant donors required for crop improvement. The study evaluated 17 medium-late duration finger millet genotypes under drought stress (DS) for 28 days during the reproductive stage to identify the traits and genotypes for drought tolerance using different statistical analysis. The photosynthetic rate (by 26.3%), stomatal conductance (by 26.4%), transpiration rate (by 24.8%) and grain yield (by 13.2%) were decreased and found sensitive to DS, but the leaf temperature was increased (4.7%). From the path analysis and multiple linear regression analysis, the mean ear weight and productive tillers were found to contribute to the grain yield significantly under well-watered conditions. While under DS conditions, the mean ear weight, productive tillers and threshing percentage equally contributed to grain yield. Based on the ranking of traits significantly contributing to grain yield, the genotype GE-4683 with a higher mean ear weight (10.65 g) was found superior to the popular variety, GPU-28. The Multiple linear regression equation predicts the possibility to increase the yield of GPU-28 under DS from the existing 360.0 to 459.5 g per square metre (by 29.1%) by the incorporation of three productive tillers instead of the existing two tillers per plant in the MLR equation. An additional 1.0 g of mean ear weight will be able to predict an increased grain yield from 360.0 to 392.0 gm−2, equivalent to 3.60 to 3.92 t/ha (by 9.4%).

Finger millet is gaining importance as a food crop with the increasing emphasis on nutritional aspects and drought resilience. However, yield improvement has stagnated. Therefore, popular varieties have been examined for the purpose of whether direct selection for grain yield can be continued or an alternate trait-based approach using the germplasm is necessary. Direct selection for grain yield over the ruling variety, cv. GPU-28 (Germplasm Unit) has not been satisfactory. The path analysis has revealed a high direct effect of mean ear weight on grain yield followed by a moderate direct effect of photosynthetic rate and leaf area index. Furthermore, backward stepwise regression analysis revealed that among the independent traits, the mean ear weight made a significant contribution (60.8%) towards grain yield, followed by the photosynthetic rate (39.2%). The regression equation predicts the inclusion of mean ear weight by 1.0 g extra (as in GE-2672) to cv. GPU-28 will increase grain yield by 4.74%. The trait-specific genotypes are superior to the cv. GPU-28 were GPU-67 (photosynthetic rate) and GE-2672 (mean ear weight) and they could be used as donors for yield improvement. Future selection would aim for genotypes having 70–75 days for flowering with 4−5 productive tillers and mean ear weight of more than 8−9 g/ear. The possible approaches for enhancing grain yield are also discussed.

Redroot pigweed (Amaranthus retroflexus L.) and robust foxtail [Setaria viridis (L.) Beauv. var. robusta-alba Schreiber (RWF) or Setaria viridis var. robusta-purpurea Schreiber (RPF)] were investigated regarding their ability to interfere with soybean [Glycine max (L.) Merr. ‘Amsoy 71′] at different weed densities and soybean row spacing throughout two growing seasons. Final weed densities for each species tended to reach a common value because of intraspecific interference regardless of the initial density. With cultivation, a narrow soybean row spacing (38 cm) resulted in less weed growth than did a wide row spacing (76 cm) but with no cultivation, the trend was reversed. Soybeans provided less interference to foxtail than to pigweed during both growing seasons. Interference from foxtail adversely affected soybean yield components and soybean seed yield more than did pigweed interference. Water-stress conditions in 1976 increased the intensity of weed interference and reduced soybean seed yield more severely than in 1975 when moisture was adequate throughout the growing season.

Field experiments were conducted in 1984 and 1985 at Stuttgart, AR, to investigate the interspecific and intraspecific interference of broadleaf signalgrass densities of 0, 10, 50, 100, and 150 plants/m2 with rice. In 1984, significant reductions in rice leaf area index (LAI) occurred 6 weeks after emergence with all broadleaf signalgrass densities. The first reduction in LAI occurred 8 weeks after emergence at the density of 150 plants/m2 in 1985. Densities of 50 plants/m2 or greater reduced rice dry weight 6 weeks after emergence in 1984, and the highest density of 150 plants/m2 reduced rice dry weight 12 weeks after emergence in 1985. Height of rice was reduced by densities of 100 and 150 plants/m2. Linear regression equations indicated that each broadleaf signalgrass plant/m2 reduced rough rice yield 18 kg/ha both years. Growth of broadleaf signalgrass was reduced by interspecific and intraspecific interference. The dry weight of broadleaf signalgrass increased at a decreasing rate at plant densities of 100 to 150/m2 when grown alone in 1984 and 1985, when a quadratic equation best described the response. Regression equations indicated interspecific interference from rice reduced broadleaf signalgrass dry weight an average of 48 and 81% in 1984 and 1985, respectively. The height of broadleaf signalgrass was greater when grown with rice than when grown alone.

Field experiments were conducted to evaluate soybean interference on common cocklebur and entireleaf morningglory under irrigated and nonirrigated conditions. Interference from the mixture of soybean and entireleaf morningglory, and soybean alone reduced the total leaf area index (LAI), LAI within the common cocklebur canopy, and growth rate of common cocklebur more than did entireleaf morningglory; more reduction occurred without irrigation than with irrigation. Irrigated common cocklebur produced 687 burs per plant, while nonirrigated produced 359. Irrigated and nonirrigated soybeans and the mixture of soybeans and entireleaf morningglory reduced common cocklebur bur production 43 to 47%. Irrigated entireleaf morningglory reduced common cocklebur bur production 42%, while nonirrigated reduced bur production 28%. Interference from the mixture of irrigated soybeans and common cocklebur reduced the total leaf area index (LAI), LAI within the entireleaf morningglory canopy, and growth rate of entireleaf morningglory more than did soybean or common cocklebur alone. Irrigated entireleaf morningglory produced 542 and 1107 seeds per plant in 1982 and 1983, respectively. The mixture of irrigated soybeans and common cocklebur reduced entireleaf morningglory seed production 84 to 90%. Nonirrigated entireleaf morningglory was not competitive in any treatment combination either year due to lack of sufficient LAI.

Field experiments were conducted to evaluate common cocklebur and entireleaf morningglory interference on soybean under irrigated and nonirrigated conditions. Total leaf area index (LAI), LAI within the soybean canopy, crop growth rate, and seed yield of soybean were decreased more by common cocklebur than by entireleaf morningglory. Interference from entireleaf morningglory, common cocklebur, or both species reduced soybean yields 21, 57, and 64%, respectively, with irrigation and 12, 60, and 76%, respectively, without irrigation. Soybean yield reduction from interference with entireleaf morningglory, common cocklebur, or both species was not influenced by soybean date of planting. Soil water was extracted from greater soil depths by soybean growing with the weeds than by soybean alone. High WUE without irrigation suggests that soybean uses water more efficiently when soil moisture is limiting than when soil moisture is available under irrigated conditions.

Monitoring grapevine canopy size and evolution during time is of great interest for the management of the vineyard. An interesting and cost effective solution for 3D characterization is provided by the Kinect sensor. To assess its practical applicability, field experiments were carried out on two different grapevines varieties (Glera and Merlot) for a three months period. The results from 3D digital imaging were compared with those achieved by direct hand-made measurements. Estimated volume was then effectively correlated to the number of leaves and to the leaf area index. The experiments demonstrated how a low cost 3D sensor can be applied for fast and repeatable reconstruction of vine vegetation, opening up for new potential improvements in variable rate application or pruning

The neotropical terrestrial insectivore Henicorhina leucosticta (Troglodytidae) maintains long-term territories through vocalizations and forages among leaf litter trapped in the understorey vegetation and ground litter. The relationship between forest structure and H. leucosticta territory size was studied in La Selva Biological Station, Costa Rica, during the non-breeding season in 2009. Forest structure was measured by assessing canopy openness and leaf area index (LAI) using hemispherical photography, while territory size was estimated with the playback technique using local conspecific vocalizations. Mean territory area was 3.8 ± 2.8 ha (mean ± SD, n = 10). Territory radius length was similar in old-growth forest and abandoned agro-forest plantations. We found that H. leucosticta territory size decreased as median LAI increased. We propose that LAI is related to territory size through the amount of leaf fall and subsequent leaf litter accumulation over the understorey plants, which constitutes an important reservoir of arthropod prey and nest materials for H. leucosticta. The long-term supply of food resources is likely to affect territory size in this species, as well as other insectivorous birds with similar foraging behaviour. These results are congruent with the structural cues hypothesis.