Effect of Light and Temperature through Poly Film Covers on Anthocyanin Content in Rose Cut Flowers

Quality is the most important attribute in rose cut flowers for both export and domestic market. Quality in cut flowers may be defined by many attributes however, among the most important is colour. A group of pigments commonly known as anthocyanins determine colour in plants. Anthocyanins play a significant role by ameliorate the effect of high irradiance in plants under stressful environment. They also play a key role in delaying senescence hence enhancing the cut flower vase life. Despite the advantages anthocyanins are affected by the preharvest conditions mainly light and temperature interfering with their stability. An experiment was set up to investigate the effect of light and temperature through selected coloured poly film covers on rose petal anthocyanin content. The greenhouse structure was covered by poly films of different colours that were compartmentalized i.e. UV-A clear, IR504 with yellow tint and UV-A 205/N with green tint replicated three times. Two rose cultivars Red calypso and Furiosa were established and maintained, upon maturity the flower heads were plucked and oven dried at 60°C to constant weight. 5 g of the crushed petals was used in anthocyanin extraction. The anthocyanins were extracted and quantified in comparison with commercial standards using HPLC machine. The data obtained from the chromatogram as peak areas was subjected to analysis of variance (ANOVA) using SAS statistical package (SAS Inst., Inc., Cary, NC) at P = .05. Where there were treatment differences, mean separation was done using Tukey’s procedure. Poly films significantly affected the quantity and quality of anthocyanin accumulation in rose petals. Cyanidin 3-0-glucoside was the most prevalent anthocyanin across all poly film covers and it was noted to be high under the UV-A 205/N (110.95±8.26 μg _ 5 g–1 DW) and IR504 (109.69±8.26 μg _ 5 g–1 DW) compared to UV-A clear (84.56± 8.26 μg _ 5 g–1 DW). The quantity of anthocyanins was low under the UV-A clear poly film that was characterized by high light transmission and day temperature. Combination of high irradiance and temperature affect the quality and quantity of anthocyanin in rose cut flowers

Curing reduces postharvest deterioration of biozyme® produced potatoes ( Solanum tuberosum L.)

Potato is among food crops that are heavily relied upon for food security assurance worldwide. Potato tubers are consumed in their fresh form and therefore require proper storage to prolong their life after harvest. Being succulent, massive losses result if bruised, exposed to light and low relative humidity. The present experiment was conducted to find optimal conductions that prolong the shelf-life of potato tubers grown using the biomass and succulence enhancing Biozyme® Potatoes were grown in a split plot experiment, arranged in a randomized complete block design. The experiment was replicated three times and repeated once. Main plots were assigned to potato cultivar (Tigoni and Asante), while subplots were assigned to Biozyme® foliar feed rate (0, 125, 250, 500 and 750 ml/ha). Each subplot was planted with 28 seed potato tubers spaced at 30 cm x 70 cm in four rows. A distance of 1 m separated adjacent subplots and main plots. After harvesting, ware potato tubers, from each treatment, were divided into four groups for four postharvest handling regimes (Cured + Dark, Cured + Room, Not Cured + Dark, and Not Cured + Room Storage). Each postharvest regime had 20 tubers, replicated four times. Weight loss, shrinkage and rotting percentages increased, but firmness decreased with increase in Biozyme® rate. The deterioration was counteracted by Curing and Dark Storage of the potato tubers that reduced weight loss, shrinkage and rotting, but increased firmness. Thus, foliar-feeding potato plants with 500 ml/ha Biozyme® followed by Curing and Dark Storage of harvested tubers are recommended to ensure high potato tuber yields and effective reduction of premature postharvest deterioration of the tubers during storage. KEYWORDS : Firmness, Rotting, Shelf-life, Shrinkage, Tuber handling, Weight loss

Pre Harvest Calcium Treatment under Selected Poly Films Improves Leaf Chlorophyll Content in Rose Cut Flower

Quality is a key attribute in marketing of cut flowers. A number of factors may determine quality in cut flowers, among them being the pre-harvest conditions under which the plant was grown. This experiment was designed to investigate the effect of light transmission through selected poly films, rose cultivar and calcium foliar feed on leaf chlorophyll content. The study site was at an elevation of 2238 m above sea level with average maximum and minimum temperature ranges from 19°C to 22°C and 5°C to 8°C respectively. The area receives a total annual rainfall ranging from 1200 to 1400 mm. The experimental design was split split plot laid down in a Randomized Complete Block Design (RCBD) with poly films forming the main plot treatments. Data collection involved use of Watch dog data logger mini weather station to determine Photosynthetically active radiation among other spectrum properties. Light transmission was evaluated using UV-1800 Shimadzu spectrophotometer. It was observed that leaf chlorophyll content increased with increase in calcium concentration in the foliar feed. Interactive effect was observed between the calcium foliar feeds and the poly film covers on stem firmness. The obtained results were consistent in both trials however the stem firmness was varied from one flush to the other. Effect of temperature caused by varying light intensity on chlorophyll content is also discussed. The results obtained show impact of environmental and nutritional factors on rose cut flower quality. &nbsp

ARPN Journal of Agricultural and Biological Science MANAGEMENT OF Fusarium oxysorum f. sp. rosae USING METHAM SODIUM, DAZOMET AND BRASSICA BIOFUMIGANTS IN GREENHOUSE ROSE (Rosa spp.) PRODUCTION

ABSTRACT Alternative strategies to manage Fusarium oxysorum f. sp. rosae in greenhouse grown rose plants were investigated at Egerton University, Department of Horticulture Research and Teaching Field in 2005 and 2006. The treatments tested included; Dazomet, metham sodium and brassica biofumigants (Brassica napus and Brassica juncea). Dazomet and metham sodium were applied at 83.3g/m 2 and 0.12g/l to 1m 2 rates, respectively. Brassica napus and Brassica juncea were uprooted at the initial flowering stage and chopped into small pieces separately. The chopped brassicas were applied to the respective plots at the rate of 2, 3 and 4 kg/m 2 . The results of this experiment showed that, Dazomet and metham sodium were effective in managing Fusarium oxysporum f.sp rosae. However their activity was quite inconsistent and short lived. Reinfestation occurred soon after field aeration. Brassica juncea at an application rate of 3 and 4 kg suppressed Fusarium oxysporum f.sp. rosae more than Brassica napus. Brassica juncea at 3 and 4 kg had a similar effect as dazomet and metham sodium in the management of Fusarium oxsporum f. sp. rosae. Although metham sodium was the most effective against Fusarium oxyporium, the Brassica biofumigants especially B. juncea at 3 kg offers a better alternative for the management of Fusarium oxysporum f.sp. rosae in greenhouse rose production

EFFICACY OF SELECTED PLANT BIOFUMIGANTS IN THE MANAGEMENT OF PARASITIC NEMATODES IN ASCLEPIAS (Asclepias tuberosa L.)

ABSTRACT Greenhouse based research to investigate the potential of using biofumigants in the management of nematodes was conducted at James Finlay's (K) . The experiment was laid in Complete Randomised Block Design replicated three times. The chopped plant materials were incorporated in the soil and left to decompose for four weeks. Nematode counts, and plant growth and flower characteristics were evaluated before and after application of soil amendment treatments. L. camara combined with nemacur reduced root knot nematodes count by between 79.8% and 82.6% while a single application of the same treatment reduced nematodes by 73.4%. Root galling was reduced by 79.3% when a combination of L. camara with nemacur was applied, while nemacur alone decreased galling by 89.6%. Nemacur or a combination of L. camara with nemacur led to an increase in plant height by between 22.7 cm and 26.5 cm respectively. L. camara with nemacur increased cumulative flower yield by between 78.6% and 83.6% compared to the untreated control. A combination of L. camara with nemacur may be used in place of synthetic nematicides alone to control nematodes and improve nutrient levels. This treatment combination gave the best control of nematodes, enhanced plant growth and significantly increased flower yield compared to all other treatments. The results from this study give cutflower growers alternative options to manage root-knot nematodes under greenhouse conditions. Flower