Studies on genetic polymorphism in Santalum Album L.

Loss of natural sandal populations due to illicit felling, forest encroachment and spike disease have an adverse effect on genetic diversity of the species. To initiate any genetic improvement programme in sandal, a precise understanding of the population genetic diversity structure is essential. The concern over the loss of genetic variability in sandal is particularly critical, as there is hardly any information regarding the diversity status of the natural populations. Identifying fast growing, disease resistant, oil rich sandal trees through breeding and their mass multiplication for afforestation are the best method for ensuring sustainable supply of superior sandalwood. The healthy sandal trees existing in heavily spike diseased area can be used as a promising starting point for any such breeding programme (Venkatesh, 1978). So far, no genetic information is available regarding the resistant nature of spike disease evaded trees left in heavily infected patches. The high rate of depletion of the superior trees in South Indian sandal reserves due to illegal felling and spike disease has necessitated an urgent need for conservation of the surviving trees.Widespread occurrence of spike disease in Marayoor forest reserve was reported in 1981 (Ghosh and Balasundaran, 1995). Because of the high density of trees and varying intensity of spike disease, Marayoor sandal population was found to be ideal for experimental studies in sandal (Ghosh et al., 1985). Fifteen trees of reserve 51 of Marayoor range had been selected as candidate plus trees for growth and spike disease evasion . These trees have been selected for mass multiplication through tissue culture technique.

Effectiveness of coir geotextiles in soil moisture conservation

Among the diversified use of coir geotextiles, its use as a protective covering to improve crop productivity and to reduce weed problem assumes to be much significant. An experiment has been conducted at Kumbazha, in Pathanamthitta district, Kerala, India to evaluate the different types of coir geotextiles and polythene as soil mulch. The treatments include different mulching materials like natural needled felt, black needled felt, rubberized coir, black polythene and transparent polythene along with a control plot (no mulch). The experiment was laid out in Completely Randomized Design with six replications. The test crops used were bhindi (var. Salkeerthi) and pineapple (var. Mauritius). The study reveals that with bhindi crop growth parameters like plant height, leaf number and lateral spread were increased by mulching with rubberized coir and transparent polythene. These two mulches caused early flowering and increased fruit yield. Coir materials as mulch recorded a yield increase ranging from 67 to 196%. Observations also reveal that weeds were not grown in plots mulched with black polythene, transparent polythene and rubberized coir. Rubberized coir as mulch enhanced the fruit yield in the case of pineapple, which is followed by natural needled felt and transparent polythene. Black polythene resisted weed growth up to 7MAP, whereas rubberized coir and transparent polythene suppressed weeds up to 8MAP. Though the weeds were grown in other treatments the weeds count was significantly lower than that of control plot. Mulching with transparent polythene enhanced the soil temperature whereas rubberized coir lowered soil temperature. More over all mulched treatments had a favourable influence in increasing soil moisture. Observing the biodegradability and eco-friendly nature of coir it could be inferred that rubberized coir can serve as good mulch for bhindi and pineapple with minimum weed problem