Investigation was conducted on the effects of early weed removal on some yield attributes of Zea mays L. var. TZB (FARZ 34) cultivated in Owerri, Nigeria with the aim of evaluating the extent of reduction in total output occasioned by delays in weed removal following seed sprouting. Healthy seeds of this variety were obtained from State Agricultural Development Corporation. The seeds were sown onto manually prepared plots in a Completely Randomized Design. Weeds on treated subplots were removed ten day following germination while those growing on the other plots (untreated) were not removed until 30 days after germination. Data on yield attribute parameters such as number of marketable cobs per plant, green earlength of undehusked cob, thousand grain weight etc. were collected. Results showed that difference in number of cobs per plant between crops harvested from treated and untreated subplots was statistically significant p<0.01. Other yield attributes investigated gave similar results with varying degrees of percentage yield differences between crops from treated and untreated subplots. The implication of this is that Zea mays competitive capability with weeds at early vegetative stages was inadequate comparable to that of the weeds. Incorporating early weed removal in the total farming plan will result in substantial yield gain for growers.
The demend of heliconias for cut flower trade is increasing day-by-day because of the long vase life, attractive colour and exotic shape. A study was conducted to standardize growth regulators for enhacing propagation efficiency in three viz., St. Vincent Red (small erect type), Golden Torch Adrian (hybrid) and Sexy Pink (large pendent type) . Two field trials were carried out for this purpose. Based on the results of the preliminary field trial, second experiment was laid out. At varietal level, significant difference was evident in the total number of suckers. In the first experiment, the variety St. Vincent Red (3.82) was significantly superior in terms of total number of suckers. However, in the second experiment, St. Vincent Red (4.06) was on par with Golden Torch Adrian (4.10). Application of growth regulators had pronounced effect on sucker production at all the stages during the first experiment when BA 750 mg l-1 produced the highest number (4.19) of total suckers. In the second experiment, variation was evident in the total number of suckers. Here, BA 850 mg l-1 produced the highest number (4.33) of suckers and it was on par with BA 700 mg l-1 (4.00) and GA3 650 mg l-1 (3.79). VG interaction exerted significant variation in the number of suckers. At varietal level, BA 750 mg l-1 produced the highest number of suckers in St. Vincent Red (4.75), GA3 500 mg l-1 in Golden TorchAdrian(4.63)and GA3 750 mg l-1 in Sexy Pink (4.00). Among VG treatment combinations in the second experiment, the highest number of suckers (4.75) in the variety St. Vincent Red was produced by BA 700 mg l-1. The varieties Golden Torch Adrian (4.88) and Sexy Pink (3.75) recorded the highest with BA 850 mg l-1. The economics of foliar application of growth regulators revealed that BA 850 mg l-1 significantly enhanced the profit in the varieties Golden Torch Adrian and Sexy Pink. Although negligible,BA 700 mg l-1 recorded slight positive response in the variety St. Vincent Red with respect to profit.
The Cytogenetic studies were carried out in two important coldwater fishes, Rainbow trout (Oncorhynchus mykiss) and Snow trout (Schizothorax richardsonii), by Giemsa staining. The diploid chromosome number (2n) in Rainbow trout (Oncorhynchus mykiss) the modal diploid number was found to be 2n = 60. The karyotype formula obtained consist of 38 metacentric (M), 6 submetacentric (Sm) and 16 telocentric chromosomes (24M + 20 Sm + 16 T). The fundamental arm number was derived to be 208 (FN = 208) and in Snow trout (Schizothorax richardsonii), the modal diploid number was found to be 2n = 96. The karyotype formula obtained consist of 18 metacentric (M), 16 submetacentric (Sm) and 12 subtelocentric and 50 telocentric chromosomes (18 M + 28 Sm + 50 T). The fundamental arm number was derived to be 284 (FN = 284). This is the attempt to compare the wild snow trout obtained from Himalayan stream and farm raised Rainbow trout in these species using conventional staining.
A field experiment was conducted at Agricultural College and research Institute, Tamil Nadu Agricultural University, Killikulam, Tamil Nadu to standardize the vegetative propagation technique in vellerukku. Three types of cuttings viz., terminal, middle and basal cuttings and three types of growth regulators viz., IBA, NAA @ 500 ppm and 1000ppm alone and in combination and control were used. The result revealed that the terminal cuttings treated with IBA 500 ppm registered the highest rooting percent (86.66 percent and 90.00 percent), number of roots (11.21 and 11.47), root length (23.75 cm and 24.98 cm), shoot length (29.40 cm and 30.64 cm) and survival percentage in the main field (68.13 percent and 71.20 percent) under both the environment viz. open and mist condition were recorded by the terminal cuttings treated with IBA 500 ppm. It was followed by terminal cuttings treated with IBA 1000 ppm. Whereas control (basal cuttings dipped in distilled water) recorded the lowest values of 18.20 and 23.28 percent of rooting, 7.03 and 7.08 number of roots, 16.14 cm and 17.12 cm root length, 19.54 cm and 20.03 cm shoot length 11.62 and 12.47 percent survival in the mainfield under both open as well as mist condition.