Effect of Different Enriched Vermicomposts, Humic Acid Extract and Indole-3-Acetic Acid Amendments on the Growth of Brassica napus

Humic acid (HA) is a specific and stable component of humus materials that behaves similarly to growth stimulants, esp. auxin hormones, contributing to improving growth indices and performance of plants. As a rich source of HA, vermicompost (VC) is also a plant growth stimulating bio-fertilizer that can enhance growth indices and performance in plants. The purpose of the present study is to compare the influence of VC enriched with bacterial and/or fertilizer, commercial humic acid (CHA) extract, and indole-3-acetic acid (IAA) on improving growth characteristics and performance of rapeseed under greenhouse conditions. The results showed the complete superiority of VC over the CHA and IAA (approximately 8% increase in the dry weights of root and aerial organ and nearly three times increase in seed weight). The highest values of these indices were obtained with VC enriched with Nitrogen, Sulfur, and Phosphorus, Azotobacter chroococcum and Pseudomonas fluorescens; the lowest value was obtained with VC enriched with urea. Additionally, the application of 3% VC and the control involved the highest and lowest values in all traits, respectively. The SPAD (chlorophyll index) value and stem diameter were not significantly affected by different application levels of VC. Overall, the applications of IAA and the CHA were not found to be suitable and therefore not recommended.

Assessment of the early growth of agarwood (Aquilaria crassna) seedlings under different sources of nutrients

The effect of different sources of nutrients on the growth of Aquilaria crassna seedlings was assessed by raising seedlings in polybags treated with inorganic fertilizer (IF), organic fertilizer (OF) and biofertilizer (BF) either alone or in combinations. The pots were established following a completely randomized block design with eight treatments: (T1) soil without IF, OF or BF ‒ control; (T2) soil + IF; (T3) soil + OF; (T4) soil + BF; (T5) soil + IF + OF; (T6) soil + IF + BF; (T7) soil + OF + BF; (T8) soil + IF + OF + BF each replicated five times. Plant height, stem diameter, dry weight of shoots and roots, leaf area and chlorophyll index were measured six months after planting. Soil pH (H₂O) and available soil P content were measured as soil parameters. The best growth performances (54.30 cm, 6.48 mm, 7.10 and 5.92 g·plant^–1, 435.33 cm² and 58 for plant height, stem diameter, shoot and root dry weight, leaf area and chlorophyll index, respectively) were recorded in T8, which also resulted in the highest available P content (18.96 mg·kg–1 soil). The lowest soil pH (H₂O) value (6.02) was recorded in T7 followed by T6 (6.17). The application of IF, OF and BF as a combination could be recommended to promote the growth of Aquilaria seedlings.

Determining nitrogen deficiencies for maize using various remote sensing indices

Determining a precise nitrogen fertilizer requirement for maize in a particular field and year has proven to be a challenge due to the complexity of the nitrogen inputs, transformations and outputs in the nitrogen cycle. Remote sensing of maize nitrogen deficiency may be one way to move nitrogen fertilizer applications closer to the specific nitrogen requirement. Six vegetation indices [normalized difference vegetation index (NDVI), green normalized difference vegetation index (GNDVI), red-edge normalized difference vegetation index (RENDVI), triangle greenness index (TGI), normalized area vegetation index (NAVI) and chlorophyll index-green (CIgreen)] were evaluated for their ability to detect nitrogen deficiency and predict grain maize grain yield. Strip trials were established at two locations in Arkansas, USA, with nitrogen rate as the primary treatment. Remote sensing data was collected weekly with an unmanned aerial system (UAS) equipped with a multispectral and thermal sensor. Relationships among index value, nitrogen fertilizer rate and maize growth stage were evaluated. Green NDVI, RENDVI and CIgreen had the strongest relationship with nitrogen fertilizer treatment. Chlorophyll Index-green and GNDVI were the best predictors of maize grain yield early in the growing season when the application of additional nitrogen was still agronomically feasible. However, the logistics of late season nitrogen application must be considered.

Association, direct and indirect effects of yield, biochemical and physiological characters on seed yield in chickpea (Cicer arietinum L.)

The present research consists of the 25 genotypes of chickpea (Cicer arietinum L.) which was carried out at the field experimentation center, Department of the Genetics and Plant Breeding, Naini Agricultural Institute, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj during Rabi 2019-20 in Randomized Block Design with three replications with an aim to determine genetic variability, correlation, direct and indirect effects yield, biochemical and physiological characters on seed yield. All the genotypes of chickpea showed significant differences among them, significance variability existed for all the characters. Based on the mean performance, high yield was found for the C-18106 followed by C-18122, C-18103, and C-18101, genotypes C-18123, ICC-15896, C-18102 & GPF-02 showed against pod borer. High heritability (?70%) coupled with high genetic advance (?20%) were being observed for the number of seeds per plant, biological yield. Seed yield per plant exhibited positive and highly significant correlation with biological yield, chlorophyll index, starch content and number of seeds per plant at both genotypic and phenotypic level. Path analysis at phenotypic level identified hundred seed weight followed by chlorophyll index, number of seeds per plant, number of secondary branches, trypsin inhibitor and harvest index important direct components for seed yield per plant. Thus, due consideration should be given to these characters during the selection.

Evaluation of Three New Citrus Rootstocks under Boron Toxicity Conditions

Boron (B) toxicity is a common limiting factor both in arid and semiarid regions, such as the Mediterranean Basin. Citrus trees are sensitive to B-toxicity, which generates a negative impact in citrus orchards. In this work, two promising citrus rootstocks (UFR-6 and 2247 x 6070-02-2) have been assessed against B-toxicity and compared with Carrizo citrange, a common commercial citrus rootstock in Mediterranean Basin. Three B concentration treatments (Control, 1 and 2.5 mM H3BO3) were established, irrigating the plants three times per week for 21 days under greenhouse conditions. During the assay, above-ground symptoms, and chlorophyll index (SPAD) were recorded. At the end of the experiment, stomatal conductance, relative water content, and B concentration in leaves and roots were determined. The increasing B concentration in plants generates visual damage in leaves for all citrus rootstocks assayed. Carrizo citrange displayed the greatest visual symptoms, decreased its chlorophyll index (SPAD), and stomatal conductance throughout the B-treatment. However, UFR-6 and 2247 x 6070-02-2 displayed less symptoms than Carrizo citrange and only reduced its parameters under the 2.5 mM H3BO3 treatment. These results can aid citrus grower rootstock planting decisions with under B-toxicity conditions.

Different substrate compositions in the development of Brazilian berry in pots

The Brazilian berry (Pliniacauliflora, sin: Myrciariacauliflora Berg), a native tree of the Brazilian Atlantic Forest, called by native people as “Jabuticaba” and cultivated throughout the national territory, is a species produced for consumption in natura, manufacturing liqueurs, ice cream, fermented drinks and juices, jellies, in addition to be used in the pharmaceutical industry for essential oil production. Despite being a tree species, it has been cultivated in pots by those who have little space. Thus, this study aimed to verify substrate compositions with soil in the development of Brazilian berry in full sun and potted. The experimental design was completely randomized, with 3 treatments and 9 replications, being: T1 – Soil + organic compost (1:1); T2 – Soil + sand (1:1); T3 – Soil + sand + organic compost (1:1:1). Chemical and physical properties of substrate mixtures, chlorophyll index and fresh and dry matter of leaves and analysis of leaf macro and micronutrients content were evaluated. Among the evaluated treatments, soil + sand + organic compost (1:1:1) showed favourable results for the evaluated characteristics, while soil + sand (1:1) showed unfavourable results, probably due to the presence of sand in its mixture.

Influence of cutting management on photosynthetic parameters, heat use efficiency and productivity of barley (Hordium vulgare L.) under variable sowing dates

Field experiments were conducted during 2015–16 and 2016–17 at Punjab Agricultural University, Ludhiana, to study the effect of staggered sowing on photosynthetic parameters, heat use efficiency and the productivity of barley (Hordium vulgare L.) in relation to different cutting management. The experiment was laid out in split plot design with three sowing dates (October 15, October 30 and November 15) in main plots and five cutting management [un-cut (control), cut at 50 days after sowing (DAS), cut at 60 DAS, cut at 50 DAS + additional 15 kg N ha-1 after cut (N15) and cut at 60 DAS + additional 15 kg N ha-1 after cut (N15)] in sub plots,replicated four times. The results indicated that photosynthetic parameters (PAR interception, chlorophyll index and normalized difference vegetation index) decreased significantly and progressively with each delay in sowing. Heat use efficiency and helio thermal use efficiency of October 15 and October 30 sown crops were statistically similar. Delay in sowing caused significant reduction in fodder, grain and biological yield of barley probably due to significant reduction in photosynthetic parameters.Nitrogen application after fodder cut improved the chlorophyll index, whereas, cutting did not influence the normalized difference vegetative index (NDVI).Un-cut crop recorded higher PAR interception.Significantly higher heat use efficiency and helio thermal use efficiency were recorded in uncutcrop. Un-cut and fodder cut at 50 DAS produced similar grain and biological yield and significantly higher than other cutting treatments. Cut at 60 DAS gave higher fodder yield but at the cost of 9.43-18.3 per cent reduction in grain yield than cut at 50 DAS. Correlation studies indicated significant positive correlation of grain yield with photosynthetic parameters, emphasizing the importance of higher growth and photosynthetic rate during reproductive period for best yield accrual from barley.

Additional Nitrogen Application Reduced White Drupelet Disorder in ‘Sweetie Pie’ Blackberry

White drupelet disorder (WDD) in blackberry (Rubus subgenus Rubus) is an abiotic condition resulting from a cultivar and environment interaction. Although high temperatures and light intensities have been implicated, little is known why this disorder manifests. Other factors, such as overall plant stress, may be contributing influences. In this study, three treatments were applied to examine whether the addition of nitrogen (N) can reduce WDD on ‘Sweetie Pie’ erect blackberry over three seasons. An initial 50 lb/acre (56.0 kg⋅ha–1) N was applied to all plots at budbreak. Two additional N application treatments of 100 kg⋅ha–1 were applied at one time (1×) or five, 20-kg⋅ha–1 applications (5×), spaced 1 week apart for 5 weeks starting at bloom. One control treatment of no additional N (0×) was also included. Berries were harvested and weighed as a total, then berries with white drupelets were separated out and weighed. The two values were divided to create a proportion and were then multiplied by 100 to determine the percentage. Nitrogen application decreased the percentage of white drupelet berries from 13.0% (control) to 10.0% (one additional application) and 9.1% (five additional applications). WDD for the 0× treatment correlated negatively to maximum high daytime temperatures during May (r = –0.58, P = 0.03) over the three seasons. Occurrence of white drupelets by treatments 0×, 1×, and 5× correlated significantly with the cumulative number of rainfall events (r = 0.49, 0.47, and 0.46, respectively). Leaf chlorophyll index and photosynthesis measurements were unaffected by treatment. Although it is likely that multiple factors are involved in the development of white drupelets, additional N may reduce the problem.

Application of UAV Remote Sensing in Monitoring Banana Fusarium Wilt

Fusarium wilt poses a current threat to worldwide banana plantation areas. To treat the Fusarium wilt disease and adjust banana planting methods accordingly, it is important to introduce timely monitoring processes. In this chapter, the multispectral images acquired by unmanned aerial vehicle (UAV) was used to establish a method to identify which banana regions were infected or uninfected with Fusarium wilt disease. The vegetation indices (VIs), including the normalised difference vegetation index (NDVI), normalised difference red edge index (NDRE), structural independent pigment index (SIPI), red-edge structural independent pigment index (SIPIRE), green chlorophyll index (CIgreen), red-edge chlorophyll index (CIRE), anthocyanin reflectance index (ARI), and carotenoid index (CARI), were selected for deciding the biophysical and biochemical characteristics of the banana plants. The relationships between the VIs and those plants infected or uninfected with Fusarium wilt were assessed using the binary logistic regression method. The results suggest that UAV-based multispectral imagery with a red-edge band is effective to identify banana Fusarium wilt disease, and that the CIRE had the best performance.

Monitoring Optical Tool to Determine the Chlorophyll Concentration in Ornamental Plants

The accurate estimation of leaf photosynthetic pigments concentration is crucial to check the plant´s health. Traditional methods of measuring photosynthetic pigments involve complex procedures of solvent extraction followed by spectrophotometric determinations. Portable plant instruments such as Soil Plant Analysis Development (SPAD) meters can facilitate this task for the speed and simplicity of the measures. The relationship between chlorophyll index obtained by SPAD-502 and pigment concentration in several ornamental species can help in the management of ornamental plant production. Two trials have been carried out in two different growing seasons (spring and summer) and facilities (greenhouse and open air), involving 30 ornamental species. There was a high linear relationship between concentrations of Chla and Chlb, as well as between Chlt and Ct in different species studied under greenhouse and open field conditions. The ratio between Chla and Chlb was higher at open field conditions and similar between Chlt and Ct. There was also a good relationship between Chlorophyll index and Chlt under both growing conditions, as well as between Chlorophyll index and Ct under greenhouse conditions. However, linear relationships with different slopes were observed for groups of species at open field conditions.