Agronomic performance of Raphanus sativus L. cultivars grown under different spacings

An ideal spacing between plants should be established for the optimization of radish (Raphanus sativus L.) crops since the plant spatial distribution of plants affects the crop yield. This study was conducted aiming to evaluate the agronomic performance of radish cultivars grown under different spacings. The experiment was conducted at the Experimental Field of the Federal Institute of Education, Science, and Technology of Maranhão, in Codó, MA, Brazil, from June to July 2017. The experiment was conducted in a randomized block design with five replications, using a 2×2 factorial arrangement. The factors consisted of 2 cultivars (Sparkler Ponta Branca and Saxa) and 2 spacings between plants (5 and 8cm), totaling 20 experimental plots. Data were collected in 6 plants from each experimental plot. The agronomic parameters: total fresh weight (TFW), root fresh weight (RFW), root mean diameter (RMD), root means length (RML), and root yield (RY) of the radish plants were evaluated. The factors (cultivars and spacing between plants) had no significant effect on TFW, RFW, RML, and RMD. The spacing between plants has a significant effect on the yield of radish crops of the cultivar Saxa, and higher yields are found when using the spacing of 5cm.

Effect of Square Planting and Nitrogen Scheduling on Yield and Micrometeorological Parameters in Maize

<p class="1">Altering plant spatial distribution induces changes in micro-meteorology of crop canopy and have cumulative effect on yield. Creation of suitable plant spatial distribution is indispensable to explore the beneficial effects of spatial pattern and it could be possible only through altering rectangular spatial distribution, which is commonly practiced in maize. Most of the nitrogen (N) scheduling approaches are growth stages based without considering crop demand and soil fertility status which may not yield better, warrants need based N management for better production in maize. The present study has investigated effects of spatial pattern and nitrogen scheduling on intercepted photosynthetically active radiation (IPAR), light extinction co-efficient (‘k’), leaf temperature (LT) and productivity of maize. The experiments were conducted during 2011 and 2012 at Tamil Nadu Agricultural University, Coimbatore. Treatments were laid out in split-plot design and replicated thrice. Treatments were: six levels of spatial pattern (60 × 25, 30 × 30, 35 × 35, 40 × 40, 45 × 45 and 50 × 50 cm). Growth stage based and need based approach of leaf color chart based (LCC) nitrogen scheduling were imposed. Field experimental results indicated that maize canopy under 30 × 30 and 35 × 35 cm spatial pattern intercepted 10 to 15% more light compared to rectangular pattern (60 × 25 cm). The ‘k’ value and leaf temperature were reduced under this pattern. Higher maize grain yield (GY) was recorded at 35 × 35 cm spatial distribution. The LCC based N scheduling recorded higher values of IPAR, LT and lower ‘k’ values. Square planting favored canopy micro-meterological parameters and which in turn enhanced grain yield of maize.</p>

THE SPATIAL DISTRIBUTION OF LIMOTHRIPS DENTICORNIS HALIDAY (THYSANOPTERA: THRIPIDAE) EGGS ON SPRING BARLEY

The within-plant spatial distribution of Limothrips denticornis Haliday eggs on spring barley (Hordeum vulgare L.) in North Dakota was examined during the growing seasons of 1987 and 1988. In both years, most eggs were found during inflorescence emergence (growth stages 10–10.5 on the Feekes scale), although eggs were detected both prior to and after these growth stages. Once inflorescence emergence was initiated, over 8.5% of the eggs were found in the top two leaf sheaths, with the majority in the flag leaf sheath. Over all barley growth stages, significantly more eggs (P≤0.05) were found in the middle third than in either the top or bottom third of the flag leaf sheath. No difference (P≥0.05) in the within-sheath location of eggs on lower leaves was detected.