Direct regeneration of banana(Musa spp.) cultivar njalipoovan through in vitro male bud culture.

Abstract

The present research work entitled “Varietal evaluation of guava (Psidium guajava L.) for urban horticulture” was conducted at the Department of Fruit Science, College of Agriculture, Vellayani, from 2023 November to 2024 October. The study was under taken to evaluate the growth and yield response of planting materials of guava to different type and size of containers and to evaluate the growth response of different varieties of guava in containers. The experiment 1 entitled “Performance evaluation of guava (Psidium guajava L.) in containers” was laid out in Completely Randomized Design (CRD) with 18 treatments and 3 replications using the guava variety Arka Kiran. The treatments included two container types (C1 - Plastic container and C2 - Air-pot), three container sizes (V1 – 40 L, V2 – 60 L and V3 – 80 L) and three different planting materials (P1 - Air layers, P2 - Rooted cuttings and P3 - Grafts). The medium of planting consisted of soil, coir pith and farm yard manure in 1 : 1 : 1 ratio across all treatment. Twelve- month-old potted plants were subjected to the study. Plants in plastic containers (C1), registered significantly taller growth with greater plant spread, primary stem girth, number of leaves per plant (at 15, 18, and 21 MAP), stem girth (at 15 and 18 MAP), root dry weight, shoot dry weight, and leaf area (at 21 MAP) compared to those in airpots. Meanwhile, plants in airpots exhibited earlier flowering, shorter duration from flowering to harvest and longer flowering duration. They also produced greater number of fruits and higher fruit weight, length, diameter and fruit yield. Among different container volumes, 80 L (V3) had the tallest plants with the highest plant spread, stem girth and primary stem girth and the highest number of leaves per plant (15 MAP, 18 MAP and 21 MAP). In addition, they exhibited earliness in flowering and harvest, highest flowering duration, fruit weight, length, diameter, number of fruits and fruit yield. Root dry weight, shoot dry weight (21 MAP) and leaf area were also the highest in V3. 168 Among the different planting materials, air layers produced taller plants with greater plant spread (at 15, 18, and 21 MAP), number of leaves per plant, leaf area and root-to-shoot ratio (at 21 MAP). In addition, they exhibited early flowering, longest flowering duration and the shortest number of days from flowering to harvest. The number of fruits, fruit weight, fruit length, diameter and fruit yield were also observed to be the highest in air layers. Grafts (P3) recorded the highest values for stem girth, primary branch girth, root dry weight and shoot dry weight. The fruits were analysed for quality parameters, including TSS, total sugar, reducing sugar, ascorbic acid, total antioxidant activity and total carotenoids. Container size, type, and planting material showed a significant difference in ascorbic acid and carotenoid content, whereas all other parameters were non-significant. Ascorbic acid and carotenoid content were higher in airpots. In terms of container volume, the 80 L containers showed higher ascorbic acid(227.67 mg 100g-1) and carotenoid levels (0.67 mg 100g-1) , while, among planting materials, air-layered plants had the highest values. Leaf tissue was analysed for physiological and biochemical parameters viz., chlorophyll content, total carotenoids, total reducing sugars and total soluble proteins at 18 MAP. Container type and planting material did not show any significant effect on these parameters, while 80 L container volume showed significantly higher total soluble proteins compared to 40 and 60 litres. The two factor interaction between container type and size (C x V), showed that 80 L plastic containers (C1V3) recorded significantly higher plant spread (E-W and N-S), stem girth, leaves per plant, leaf area and root dry weight. The shoot dry weight was higher in both plastic container and air-pots with 80 L (C1V3 and C2V3). Air-pots with 80 L (C2V3), exhibited early flowering with more fruits per plant, enhanced flowering duration, earlier flowering to harvest and the highest fruit weight, length, diameter and fruit yield. Interaction between container type and planting material (C x P) also confirms similar results in air-pots with air layers (C2P1). Root : shoot ratio was the highest in air-pots with grafted plants (C2P3). The two factor interaction between container size and planting material (V x P) showed that air layers grown in 80 L containers (V3P1) outperformed other combinations with respect to plant height, plant 169 spread, leaves per plant, leaf area, number of fruits, flowering duration, days to flowering, days from flowering to harvest, fruit weight, length, diameter and fruit yield. Shoot dry weight, stem girth and primary stem girth were the highest in 80 L with graft (V3P3). In three factor interaction, 80 L plastic containers with graft (C1V3P3) showed higher root dry weight and shoot dry weight while plant height and leaf area were the highest for air layers in 80 L plastic container (C1V3P1). The least number of days to flowering and days from flowering to harvest were observed in 80 L airpots with air layers (C2V3P1) they also produced the highest number of leaves and fruits, as well as the greatest fruit weight, length, diameter and fruit yield. Another notable feature observed in the study is the presence of root coiling in plastic containers of all sizes (40, 60, and 80 L), regardless of the type of planting material. In contrast, root coiling was absent in airpots of all container sizes. This study underscores the importance of selecting appropriate container types, sizes, and planting materials for successful guava cultivation in containers. Airpots outperformed plastic containers by enhancing reproductive traits like early flowering, extended flowering duration, and superior fruit yield and quality. Larger containers (80 L) showed the best results across growth, fruit yield and biochemical parameters, including ascorbic acid and carotenoids. Among planting materials, air layers excelled in vegetative growth, earliness in flowering, and fruit quality, establishing 80 L airpots with air layers as the optimal choice for container-based guava cultivation. The experiment 2 entitled “Varietal evaluation of guava (Psidium guajava L.) for urban horticulture” was laid out in Completely Randomized Design (CRD) with 5 treatments and 3 replications. The treatments included five varieties of air layered guava: T1-Allahabad Safeda, T2-Lucknow 49, T3-Arka Kiran, T4-Arka Rashmi and T5- Arka Mridula. (Note: The best container type, container size and planting material (Airpots 80 L air layers) was selected from the result of first year observations of the experiment entitled “Performance evaluation of guava (Psidium guajava L.) in container and used in this experiment). T5-Arka Mridula registered the highest plant 170 height, primary and the secondary stem girth, while early flowering with highest number of flowers was registered in T4-Arka Rashmi. Leaf tissue was analysed for physiological and biochemical parameters viz., chlorophyll content, total carotenoids, total reducing sugars and total soluble proteins at 6 MAP. Total chlorophyll (0.98 mg 100 g -1), reducing sugar (1.84%) and carotenoid content(0.70 mg 100 g -1) were the highest in T5-Arka Mridula and total soluble protein was the highest in T1-Allahabad Safeda. This study emphases the importance of the growth response of different varieties of guava in containers. Among vegetative parameters, plant height, primary and secondary stem girth were the highest in Arka Mridula which was reflected in physiological and biochemical parameters like chlorophyll, reducing sugar and carotenoid contents that gave the highest values. However, in plant spread and flowering parameters like days to flowering and number of flowers the highest values were in Arka Rashmi. Plants with a compact canopy and good reproductive parameters are ideal for container growing. Thus, the present study unveils the suitability of Arka Rashmi for container growing of guava.