Need to Counter the White Stem Borer Scourge
L.V. Ananda Rao
Arabica Production in India has significantly increased since 1950s. This was possible due to large-scale cultivations of newer cultivars and efforts of growers in adopting intensive cultivation practices not withstanding the fact that coffee production was dependent on various weather parameters. The growers adopted high standards of cultivation practices, which encompassed the integrated strategies effective management of Leaf Rust & White Stem Borer with mandatory schedule & implementation of prophylactic Fungicidal Sprays and Pesticide swabbing respectively. Thus growers had by and large achieved economic viability of Arabica production by maintaining two-tier shade pattern and meticulously implementing spraying and swabbing operation against Leaf Rust and White Stem Borer as the said leaf disease and stem borer were potential limiting factors of production.
The changing weather patterns coupled with longer drought periods experienced during the past 4 to 5 seasons has disrupted the schedule of implementing the mandatory spray/swabbing schedule. The situation became the predisposing factors for accentuating the incidence of White stem borer and consequent loss of productive plants. This apart non- availability of alternate and effective pesticides on par with BHC/Lindane resulted in impairment of the integrated crop management system.
As such in the present circumstances the scourage of WSB has assumed alarming proportions since 3 to 4 seasons and it is imperative to contain the incidence effectively by reviving efforts on building up of the shade intensity and implementing physical/ primary measures such as borer tracing and immediate destruction of borer infested plants.
The successful step to intensify shade in exposed areas is to develop lower canopy shade with dadaps. It may be recalled that the price boom period in early 1990s prompted many cultivators to adopt high production technology in terms of application of higher levels of nurtion and crop management with reduced levels of shade intensity to exploit crop production potential. Although, this strategy yielded additional crop in quantity, the shortcut to realize such increased production caused deterioration of plant vigor/health. Subsequently the growers became cash strapped in view of falling prices for coffee. Further, fall in revenues from coffee forced growers to economize on input levels both in terms of farm input and labour.
The cumulative effective of disturbed/ changed micro-climate on individual holdings affected the production potential, continued spells of drought situation, inadequate monsoon and the uninterrupted slide in coffee prices have certainly threatened the competitiveness of Indian Arabica producers and reiterates the need to initiate steps to effectively reduce the crop losses and to regain the economic viability of Arabica production. This is mainly possible by improvement of productivity and reestablishing proper microclimate on individual plantations.
The present arabica coffee scenario depicts the need for every Arabica grower to adopt maximum measures to reestablish the microclimate on Arabica farms. Such measures shall have the component of integrated means focused to combat the white stem borer incidence. Although, the chemical control measure forms an important part of the integrated pest management programme it is to be resorted only as an ultimate step and not to be prioritized under any circumstances.
Effective measures to manage and reduce incidence of white stem borer on arabica holdings could be focussed on:
- Development of mixed varieties of shade to optimum levels and ensure proper shading to arabica blocks.
- Careful Bush Management practices wherein excess centering or pruning or exposing the main stem is avoided.
- Borer tracing practice through out the year to identify/destroy infested plants to be adopted.
- Minimize extraction of plants or loss of framework by stumping only after confirming infestation symptoms such as raised ridges/ brown circles on the bark at collar region, present of exit holes etc. Arrange immediate destruction of affected stems to avoid storing of affected stems/stumps on the plantations.
- Supply plant and fill the vacancies in all the blocks, preferably with similar high yielding genotype to maintain plant density, homogeneity and also to avoid variation in cup quality.
- Reestablishment of lower canopy shade with erythrina litho sperma (dadap) and supplement Silver Oak shaded blocks with mixed species of jungle trees to maximum extent possible to ensure sufficient soil moisture during post-monsoon period on the endemic blocks.
In order to support and supplement the efforts of the Arabica coffee growers for gap filling, in filling and replantation, the concept of group nurseries to raise plant material and meet the requirement of small growers is promoted by the Board with financial assistance etc.
The Integrated Pest Management Plots established by the Board across the arabica coffee tracts have helped providing continuous awareness and education to the small coffee growers on the WSB management strategies.
The scheme to provide financial incentives @ Rs. 2 per grub, Rs. 3 per pupae and Rs. 5 per beetle has encouraged the Arabica growers in adopting eco friendly control measures against White Stem Borer during the past year. The tremendous efforts put forth by the participating growers in adopting and encouraging the catch and kill strategy would certainly reduce the pest inoculun in the coming seasons.
The Board envisages to exter assistance to growers in future I providing Synthetic Pheromone, tral and supply of bio-agent/Parasitoid to encourage adoption of biologic control measures against the Whi Stem Borer.
The exploration of gene technolo> to evolve White Stem Borer resista Arabica Cultivator is already initiatf in coffee research and a break throul would serve, to end the menace white stem borer in future.
